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Full vulnerability report · 2026
CVE-2026-40355High confidence

An unauthenticated remote attacker can trigger this, causing the process to terminate in parse_nego_message

MIT · Kerberos 5

5.9MediumCVSS 3.1
Recommended action
Within 7 days

Medium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Patch available
Distribution package intelligence

Ubuntu vendor package status

Canonical’s release and source-package findings are shown separately from local repository availability.

1 package state
Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Ubuntu releaseSource packageVendor stateFixed versionEvidence
Ubuntu 24.04 LTSnoble · standard archivekrb5Vendor fix publishedCanonical reports that a fixed source package version has been published. Repository candidate availability is not checked by BlackTree.1.20.1-6ubuntu2.7Canonical record ↗Source updated 9 Sept 2026
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

3 current
SSA-019113 · CSAF 2.0 · revision 2 · interimSiemens ProductCERTSSA-019113: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1.6
5 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= V3.1.6
  • SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= V3.1.6
  • SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= V3.1.6
  • SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= V3.1.6
  • SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= V3.1.6
Summary
In MIT Kerberos 5 (aka krb5) before 1.22.3, there is a NULL pointer dereference if an application calls gss_accept_sec_context() on a system with a NegoEx mechanism registered in /etc/gss/mech. An unauthenticated remote attacker can trigger this, causing the process to terminate in parse_nego_message.
Remediation
Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.
CVE-2026-40355 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitykrb5: MIT Kerberos 5: Denial of Service via NULL pointer dereference in NegoEx mechanism
18 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • krb5-devel as a component of Red Hat Enterprise Linux 6
  • krb5-libs as a component of Red Hat Enterprise Linux 6
  • krb5-pkinit-openssl as a component of Red Hat Enterprise Linux 6
  • krb5-server as a component of Red Hat Enterprise Linux 6
  • krb5-server-ldap as a component of Red Hat Enterprise Linux 6
  • krb5-workstation as a component of Red Hat Enterprise Linux 6
  • krb5.src as a component of Red Hat Enterprise Linux 6
  • libkadm5 as a component of Red Hat Enterprise Linux 6
  • krb5-devel as a component of Red Hat Enterprise Linux 7
  • krb5-libs as a component of Red Hat Enterprise Linux 7
  • krb5-pkinit as a component of Red Hat Enterprise Linux 7
  • krb5-server as a component of Red Hat Enterprise Linux 7
Summary
A flaw was found in MIT Kerberos 5 (krb5). An unauthenticated remote attacker can exploit a NULL pointer dereference vulnerability by calling `gss_accept_sec_context()` on a system with a NegoEx mechanism registered. This can lead to the termination of the process, resulting in a Denial of Service (DoS).
Remediation
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
SSA-082556 · CSAF 2.0 · revision 7 · interimSiemens ProductCERTSSA-082556: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1.5
5 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= V3.1.5
  • SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= V3.1.5
  • SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= V3.1.5
  • SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= V3.1.5
  • SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= V3.1.5
Summary
In MIT Kerberos 5 (aka krb5) before 1.22.3, there is a NULL pointer dereference if an application calls gss_accept_sec_context() on a system with a NegoEx mechanism registered in /etc/gss/mech. An unauthenticated remote attacker can trigger this, causing the process to terminate in parse_nego_message.
Remediation
Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-25981

No EUVD known-exploited evidence

In MIT Kerberos 5 (aka krb5) before 1.22.3, there is a NULL pointer dereference if an application calls gss_accept_sec_context() on a system with a NegoEx mechanism registered in /etc/gss/mech. An unauthenticated remote attacker can trigger this, causing the process to terminate in parse_nego_message.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
5.9 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

Medium technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

In MIT Kerberos 5 (aka krb5) before 1.22.3, there is a NULL pointer dereference if an application calls gss_accept_sec_context() on a system with a NegoEx mechanism registered in /etc/gss/mech. An unauthenticated remote attacker can trigger this, causing the process to terminate in parse_nego_message.

What

In MIT Kerberos 5 (aka krb5) before 1.22.3, there is a NULL pointer dereference if an application calls gss_accept_sec_context() on a system with a NegoEx mechanism registered in /etc/gss/mech. An unauthenticated remote attacker can trigger this, causing the process to terminate in parse_nego_message.

Why

The product dereferences a pointer that it expects to be valid but is NULL.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

In MIT Kerberos 5 (aka krb5) before 1.22.3, there is a NULL pointer dereference if an application calls gss_accept_sec_context() on a system with a NegoEx mechanism registered in /etc/gss/mech. An unauthenticated remote attacker can trigger this, causing the process to terminate in parse_nego_message.

Why

The product dereferences a pointer that it expects to be valid but is NULL.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Reference recorded

A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.

Likely attack path
a network path → NULL Pointer Dereference → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
High: exploitation depends on specific conditions
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-476 ↗

CWE-476: NULL Pointer Dereference. The product dereferences a pointer that it expects to be valid but is NULL.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedCWE-476Public exploit reference
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2026-25981Official EUVD mapping

In MIT Kerberos 5 (aka krb5) before 1.22.3, there is a NULL pointer dereference if an application calls gss_accept_sec_context() on a system with a NegoEx mechanism registered in /etc/gss/mech. An unauthenticated remote attacker can trigger this, causing the process to terminate in parse_nego_message.

Official EUVD record
BSI · German · WID-SEC-W-2026-1290MIT Kerberos: Mehrere Schwachstellen ermöglichen Denial of Service

Ein Angreifer kann mehrere Schwachstellen in MIT Kerberos ausnutzen, um einen Denial of Service Angriff durchzuführen.

Official advisory
CERT-FR · French · CERTFR-2026-AVI-0880Multiples vulnérabilités dans les produits Siemens

26-31441, CVE-2026-31446, CVE-2026-31447, CVE-2026-31448, CVE-2026-31450, CVE-2026-31452, CVE-2026-31466, CVE-2026-31469, CVE-2026-31485, CVE-2026-31494, CVE-2026-31495, CVE-2026-31496, CVE-2026-31503, CVE-2026-31504, CVE-2026-31507, CVE-2026-31508, CVE-2026-31515, CVE-2026-31518, CVE-2026-31521, CVE-2026-31533, CVE-2026-31546, CVE-2026-31555, CVE-2026-31563, CVE-2026-31565, CVE-2026-31628, CVE-2026-31634, CVE-2026-31649, CVE-2026-31651, CVE-2026-31658, CVE-2026-31664, CVE-2026-31665, CVE-2026-31669, CVE-2026-31670, CVE-2026-31671, CVE-2026-31674, CVE-2026-31680, CVE-2026-31682, CVE-2026-31737, CVE-2026-31752, CVE-2026-31761, CVE-2026-31768, CVE-2026-40355, CVE-2026-41989, CVE-2026-43011, CVE-2026-43024, CVE-2026-43025, CVE-2026-43026, CVE-2026-43027, CVE-2026-43028, CVE-2026-43030, CVE-2026-43033, CVE-2026-43035, CVE-2026-43038, CVE-2026-43040, CVE-2026-43057, CVE-2026-43284, CVE-2026-46174, CVE-2026-46300 et CVE-2026-46333. SIMATIC S7-PLCSIM Advanced toutes versions pour la vulnérabilité CVE-2026-54429 Résumé De multiples vulnérabilités ont été découvertes dans les produits Siemens. Certaines d'entre elles permettent à un attaquant de provoquer une exécution de code arbitraire à distance, une élévation de privilèges et un déni de service à distance. Solutions Se référer au bulletin de sécuri

Official advisory
CERT-FR · French · CERTFR-2026-AVI-0788Multiples vulnérabilités dans les produits IBM

d?id=CVE-2026-32635 Référence CVE CVE-2026-33671 https://www.cve.org/CVERecord?id=CVE-2026-33671 Référence CVE CVE-2026-33672 https://www.cve.org/CVERecord?id=CVE-2026-33672 Référence CVE CVE-2026-33750 https://www.cve.org/CVERecord?id=CVE-2026-33750 Référence CVE CVE-2026-33814 https://www.cve.org/CVERecord?id=CVE-2026-33814 Référence CVE CVE-2026-34268 https://www.cve.org/CVERecord?id=CVE-2026-34268 Référence CVE CVE-2026-34282 https://www.cve.org/CVERecord?id=CVE-2026-34282 Référence CVE CVE-2026-39821 https://www.cve.org/CVERecord?id=CVE-2026-39821 Référence CVE CVE-2026-39824 https://www.cve.org/CVERecord?id=CVE-2026-39824 Référence CVE CVE-2026-40355 https://www.cve.org/CVERecord?id=CVE-2026-40355 Référence CVE CVE-2026-40356 https://www.cve.org/CVERecord?id=CVE-2026-40356 Référence CVE CVE-2026-40973 https://www.cve.org/CVERecord?id=CVE-2026-40973 Référence CVE CVE-2026-40975 https://www.cve.org/CVERecord?id=CVE-2026-40975 Référence CVE CVE-2026-40977 https://www.cve.org/CVERecord?id=CVE-2026-40977 Référence CVE CVE-2026-41035 https://www.cve.org/CVERecord?id=CVE-2026-41035 Référence CVE CVE-2026-41238 https://www.cve.org/CVERecord?id=CVE-2026-41238 Référence CVE CVE-2026-41239 https://www.cve.org/CVERecord?id=CVE-2026-41239 Référence CVE CVE-2026-41240 https://www.cve.org/CVERecord?id=

Official advisory
CERT-FR · French · CERTFR-2026-AVI-0571Multiples vulnérabilités dans Microsoft Azure

De multiples vulnérabilités ont été découvertes dans Microsoft Azure. Elles permettent à un attaquant de provoquer un problème de sécurité non spécifié par l'éditeur.

Official advisory
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= V3.1.6; SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= V3.1.6; SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= V3.1.6; SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= V3.1.6; SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= V3.1.6
Fixed
An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.
04

Evidence and provenance

Published 28 Apr 2026 · Last source change 8 Sept 2026, 08:48 UTC · CWE-476 · NULL Pointer Dereference

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-25981
Product sourceVendor CSAF · Siemens ProductCERT
Remediation sourceVendor CSAF · Siemens ProductCERT
CWE sourceCNA
NVD statusNVD modified after enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates →
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    krb5-devel as a component of Red Hat Enterprise Linux 6; krb5-libs as a component of Red Hat Enterprise Linux 6; krb5-pkinit-openssl as a component of Red Hat Enterprise Linux 6; krb5-server as a component of Red Hat Enterprise Linux 6; krb5-server-ldap as a component of Red Hat Enterprise Linux 6; krb5-workstation as a component of Red Hat Enterprise Linux 6; krb5.src as a component of Red Hat Enterprise Linux 6; libkadm5 as a component of Red Hat Enterprise Linux 6; krb5-devel as a component of Red Hat Enterprise Linux 7; krb5-libs as a component of Red Hat Enterprise Linux 7; krb5-pkinit as a component of Red Hat Enterprise Linux 7; krb5-server as a component of Red Hat Enterprise Linux 7; krb5-server-ldap as a component of Red Hat Enterprise Linux 7; krb5-workstation as a component of Red Hat Enterprise Linux 7; krb5.src as a component of Red Hat Enterprise Linux 7; libkadm5 as a component of Red Hat Enterprise Linux 7; openshift/ose-rhel-coreos-9 as a component of Red Hat OpenShift Container Platform 4 · Fixed: krb5-debuginfo-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debuginfo-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debuginfo-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debuginfo-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debugsource-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debugsource-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debugsource-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debugsource-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-devel-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-devel-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-devel-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-devel-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-libs-debuginfo-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-libs-debuginfo-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-libs-debuginfo-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-libs-debuginfo-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-pkinit-debuginfo-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-pkinit-debuginfo-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-pkinit-debuginfo-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-pkinit-debuginfo-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-debuginfo-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-debuginfo-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-debuginfo-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-debuginfo-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-ldap-debuginfo-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-ldap-debuginfo-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-ldap-debuginfo-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-ldap-debuginfo-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-workstation-debuginfo-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-workstation-debuginfo-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); and 301 more
    After
    krb5-devel as a component of Red Hat Enterprise Linux 6; krb5-libs as a component of Red Hat Enterprise Linux 6; krb5-pkinit-openssl as a component of Red Hat Enterprise Linux 6; krb5-server as a component of Red Hat Enterprise Linux 6; krb5-server-ldap as a component of Red Hat Enterprise Linux 6; krb5-workstation as a component of Red Hat Enterprise Linux 6; krb5.src as a component of Red Hat Enterprise Linux 6; libkadm5 as a component of Red Hat Enterprise Linux 6; krb5-devel as a component of Red Hat Enterprise Linux 7; krb5-libs as a component of Red Hat Enterprise Linux 7; krb5-pkinit as a component of Red Hat Enterprise Linux 7; krb5-server as a component of Red Hat Enterprise Linux 7; krb5-server-ldap as a component of Red Hat Enterprise Linux 7; krb5-workstation as a component of Red Hat Enterprise Linux 7; krb5.src as a component of Red Hat Enterprise Linux 7; libkadm5 as a component of Red Hat Enterprise Linux 7; openshift/ose-rhel-coreos-8 as a component of Red Hat OpenShift Container Platform 4; openshift/ose-rhel-coreos-9 as a component of Red Hat OpenShift Container Platform 4 · Fixed: krb5-debuginfo-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debuginfo-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debuginfo-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debuginfo-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debugsource-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debugsource-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debugsource-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debugsource-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-devel-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-devel-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-devel-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-devel-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-libs-debuginfo-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-libs-debuginfo-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-libs-debuginfo-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-libs-debuginfo-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-pkinit-debuginfo-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-pkinit-debuginfo-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-pkinit-debuginfo-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-pkinit-debuginfo-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-debuginfo-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-debuginfo-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-debuginfo-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-debuginfo-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-ldap-debuginfo-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-ldap-debuginfo-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-ldap-debuginfo-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-ldap-debuginfo-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-workstation-debuginfo-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-workstation-debuginfo-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); and 301 more
    Red Hat Product Security ↗
  2. Affected versionsThe structured affected or fixed version information changed.
    Before
    krb5-devel as a component of Red Hat Enterprise Linux 6; krb5-libs as a component of Red Hat Enterprise Linux 6; krb5-pkinit-openssl as a component of Red Hat Enterprise Linux 6; krb5-server as a component of Red Hat Enterprise Linux 6; krb5-server-ldap as a component of Red Hat Enterprise Linux 6; krb5-workstation as a component of Red Hat Enterprise Linux 6; krb5.src as a component of Red Hat Enterprise Linux 6; libkadm5 as a component of Red Hat Enterprise Linux 6; krb5-devel as a component of Red Hat Enterprise Linux 7; krb5-libs as a component of Red Hat Enterprise Linux 7; krb5-pkinit as a component of Red Hat Enterprise Linux 7; krb5-server as a component of Red Hat Enterprise Linux 7; krb5-server-ldap as a component of Red Hat Enterprise Linux 7; krb5-workstation as a component of Red Hat Enterprise Linux 7; krb5.src as a component of Red Hat Enterprise Linux 7; libkadm5 as a component of Red Hat Enterprise Linux 7; openshift/ose-rhel-coreos-9 as a component of Red Hat OpenShift Container Platform 4 · Fixed: krb5-debuginfo-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debuginfo-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debuginfo-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debuginfo-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debugsource-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debugsource-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debugsource-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debugsource-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-devel-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-devel-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-devel-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-devel-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-libs-debuginfo-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-libs-debuginfo-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-libs-debuginfo-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-libs-debuginfo-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-pkinit-debuginfo-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-pkinit-debuginfo-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-pkinit-debuginfo-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-pkinit-debuginfo-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-debuginfo-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-debuginfo-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-debuginfo-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-debuginfo-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-ldap-debuginfo-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-ldap-debuginfo-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-ldap-debuginfo-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-ldap-debuginfo-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-workstation-debuginfo-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-workstation-debuginfo-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); and 298 more
    After
    krb5-devel as a component of Red Hat Enterprise Linux 6; krb5-libs as a component of Red Hat Enterprise Linux 6; krb5-pkinit-openssl as a component of Red Hat Enterprise Linux 6; krb5-server as a component of Red Hat Enterprise Linux 6; krb5-server-ldap as a component of Red Hat Enterprise Linux 6; krb5-workstation as a component of Red Hat Enterprise Linux 6; krb5.src as a component of Red Hat Enterprise Linux 6; libkadm5 as a component of Red Hat Enterprise Linux 6; krb5-devel as a component of Red Hat Enterprise Linux 7; krb5-libs as a component of Red Hat Enterprise Linux 7; krb5-pkinit as a component of Red Hat Enterprise Linux 7; krb5-server as a component of Red Hat Enterprise Linux 7; krb5-server-ldap as a component of Red Hat Enterprise Linux 7; krb5-workstation as a component of Red Hat Enterprise Linux 7; krb5.src as a component of Red Hat Enterprise Linux 7; libkadm5 as a component of Red Hat Enterprise Linux 7; openshift/ose-rhel-coreos-9 as a component of Red Hat OpenShift Container Platform 4 · Fixed: krb5-debuginfo-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debuginfo-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debuginfo-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debuginfo-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debugsource-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debugsource-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debugsource-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-debugsource-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-devel-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-devel-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-devel-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-devel-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-libs-debuginfo-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-libs-debuginfo-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-libs-debuginfo-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-libs-debuginfo-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-pkinit-debuginfo-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-pkinit-debuginfo-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-pkinit-debuginfo-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-pkinit-debuginfo-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-debuginfo-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-debuginfo-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-debuginfo-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-debuginfo-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-ldap-debuginfo-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-ldap-debuginfo-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-ldap-debuginfo-0:1.21.3-10.el10_2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-server-ldap-debuginfo-0:1.21.3-10.el10_2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-workstation-debuginfo-0:1.21.3-10.el10_2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10); krb5-workstation-debuginfo-0:1.21.3-10.el10_2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 10); and 301 more
    Red Hat Product Security ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2026-25981↗Vendor CSAF · Siemens ProductCERT↗CISA Vulnrichment SSVC evidence↗CVE authority or vendor reference↗Public exploit reference↗Patch or update reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-40355 · cve.blacktree.nl