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Full vulnerability report · 2026
CVE-2026-6245High confidence

Sssd: out-of-bounds read in the sssd

Red Hat · Red Hat Enterprise Linux 10

5.5MediumCVSS 3.1
Recommended action
Patch only the product branches with a verified fix

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 167 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Low, lowered one band.downgradedsince 1 Sep 2026

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • Exploitation requires an existing local or physical foothold with privileges.
  • EPSS is 0.15% for the current model date.

Compensating controls

  • Apply the linked authoritative mitigation while planning the permanent fix.
  • Restrict local access and enforce least privilege on affected hosts.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Red Hat Red Hat Enterprise Linux 10 and falls inside the recorded affected range.
  2. Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: No default targetRemediation target: Normal maintenance

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Cross-source reconciliation

Remediation availability differs by product scope

Verified remediation exists for at least one product or source, but 167 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Distribution package intelligence

Release-specific package status

Debian, ubuntu findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.

4 package states
Package result overrides the generic status

BlackTree has verified remediation for at least one product or source, but the relevant distribution still reports no fixed package for 1 affected package state shown here. Treat those rows as affected with no fix until that distribution publishes a fixed version.

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.

Distribution releaseSource packageVendor stateFixed versionEvidence
Debian trixietrixie · sourcesssdAffected, no fix publishedDebian currently tracks this release as open.Not published in this feedDebian Security Tracker ↗Source updated 5 Oct 2026
Debian bookwormbookworm · sourcesssdNot affectedDebian marks this release not affected (fixed-version marker 0).Not published in this feedDebian Security Tracker ↗Source updated 5 Oct 2026
Debian sidsid · sourcesssdVendor fix publishedDebian records a fixed source-package version for this release.2.13.1-1Debian Security Tracker ↗Source updated 5 Oct 2026
Ubuntu 24.04 LTSnoble · standard archivesssdVendor fix publishedCanonical reports that a fixed source package version has been published. Repository candidate availability is not checked by BlackTree.2.9.4-1.1ubuntu6.5Canonical Ubuntu Security ↗Source updated 5 Oct 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.

1 current
CVE-2026-6245 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitysssd: out-of-bounds read in the sssd
166 known affected

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

  • libipa_hbac as a component of Red Hat Enterprise Linux 10
  • libsss_autofs as a component of Red Hat Enterprise Linux 10
  • libsss_certmap as a component of Red Hat Enterprise Linux 10
  • libsss_idmap as a component of Red Hat Enterprise Linux 10
  • libsss_nss_idmap as a component of Red Hat Enterprise Linux 10
  • libsss_nss_idmap-devel as a component of Red Hat Enterprise Linux 10
  • libsss_sudo as a component of Red Hat Enterprise Linux 10
  • python3-libipa_hbac as a component of Red Hat Enterprise Linux 10
  • python3-libsss_nss_idmap as a component of Red Hat Enterprise Linux 10
  • python3-sss as a component of Red Hat Enterprise Linux 10
  • python3-sss-murmur as a component of Red Hat Enterprise Linux 10
  • python3-sssdconfig as a component of Red Hat Enterprise Linux 10
Summary
A flaw was found in the System Security Services Daemon (SSSD). The pam_passkey_child_read_data() function within the PAM passkey responder fails to properly handle raw bytes received from a pipe. Because the data is treated as a NUL-terminated C string without explicit termination, it results in an out-of-bounds read when processed by functions like snprintf(). A local attacker could potentially trigger this vulnerability by initiating a crafted passkey authentication request, causing the SSSD PAM responder to crash, resulting in a local Denial of Service (DoS).
Remediation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Optional official sources

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

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

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-2026-23032

No EUVD known-exploited evidence

A flaw was found in the System Security Services Daemon (SSSD). The pam_passkey_child_read_data() function within the PAM passkey responder fails to properly handle raw bytes received from a pipe. Because the data is treated as a NUL-terminated C string without explicit termination, it results in an out-of-bounds read when processed by functions like snprintf(). A local attacker could potentially trigger this vulnerability by initiating a crafted passkey authentication request, causing the SSSD PAM responder to crash, resulting in a local Denial of Service (DoS).

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
5.5 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionPatch only the product branches with a verified fix

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority. Verified remediation exists for at least one product or source, but 167 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
01

What, why and how

A flaw was found in the System Security Services Daemon (SSSD). The pam_passkey_child_read_data() function within the PAM passkey responder fails to properly handle raw bytes received from a pipe. Because the data is treated as a NUL-terminated C string without explicit termination, it results in an out-of-bounds read when processed by functions like snprintf(). A local attacker could potentially trigger this vulnerability by initiating a crafted passkey authentication request, causing the SSSD PAM responder to crash, resulting in a local Denial of Service (DoS).

What

A flaw was found in the System Security Services Daemon (SSSD). The pam_passkey_child_read_data() function within the PAM passkey responder fails to properly handle raw bytes received from a pipe. Because the data is treated as a NUL-terminated C string without explicit termination, it results in an out-of-bounds read when processed by functions like snprintf(). A local attacker could potentially trigger this vulnerability by initiating a crafted passkey authentication request, causing the SSSD PAM responder to crash, resulting in a local Denial of Service (DoS).

Why

The product uses a sequential operation to read or write a buffer, but it uses an incorrect length value that causes it to access memory that is outside of the bounds of the buffer.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may disrupt the affected service.

What

A flaw was found in the System Security Services Daemon (SSSD). The pam_passkey_child_read_data() function within the PAM passkey responder fails to properly handle raw bytes received from a pipe. Because the data is treated as a NUL-terminated C string without explicit termination, it results in an out-of-bounds read when processed by functions like snprintf(). A local attacker could potentially trigger this vulnerability by initiating a crafted passkey authentication request, causing the SSSD PAM responder to crash, resulting in a local Denial of Service (DoS).

Why

The product uses a sequential operation to read or write a buffer, but it uses an incorrect length value that causes it to access memory that is outside of the bounds of the buffer.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may disrupt the affected service.

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.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
local access → Buffer Access with Incorrect Length Value → disrupt the affected service
Attack surface
Local
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
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-805 ↗

CWE-805: Buffer Access with Incorrect Length Value. The product uses a sequential operation to read or write a buffer, but it uses an incorrect length value that causes it to access memory that is outside of the bounds of the buffer.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:L/AC:L/PR:L/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.

AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level 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
The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
Denial of serviceCWE-805
A

Official authority intelligence

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

ENISA EUVD · EUVD-2026-23032Official EUVD mapping

A flaw was found in the System Security Services Daemon (SSSD). The pam_passkey_child_read_data() function within the PAM passkey responder fails to properly handle raw bytes received from a pipe. Because the data is treated as a NUL-terminated C string without explicit termination, it results in an out-of-bounds read when processed by functions like snprintf(). A local attacker could potentially trigger this vulnerability by initiating a crafted passkey authentication request, causing the SSSD PAM responder to crash, resulting in a local Denial of Service (DoS).

Official EUVD record ↗
Cyber Security Agency of Singapore · English · CSA-SB-20260422Security Bulletin 22 April 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 22 April 2026, published on 22 April 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-028079Fedora Project等の複数ベンダの製品における不適切な長さの値によるバッファへのアクセスに関する脆弱性

System Security Services Daemon（SSSD）に脆弱性が発見されました。PAMパスキー応答プログラム内の pam_passkey_child_read_data() 関数が、パイプから受信した生のバイトデータを適切に処理できません。このデータは明示的な終端なしにNUL終端のC文字列として扱われるため、snprintf() のような関数で処理される際に境界外読み取りが発生します。ローカルの攻撃者は、細工されたパスキー認証要求を開始することでこの脆弱性を悪用し、SSSD PAM応答プログラムをクラッシュさせることでローカルでのサービス拒否（DoS）を引き起こす可能性があります。

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.
Fix availability varies by product
Affected
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
Workaround
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
04

Evidence and provenance

Published 15 Apr 2026 · Last source change 1 Sept 2026, 11:44 UTC · CWE-805 · Buffer Access with Incorrect Length Value

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-2026-23032
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD enriched

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
    libipa_hbac as a component of Red Hat Enterprise Linux 10; libsss_autofs as a component of Red Hat Enterprise Linux 10; libsss_certmap as a component of Red Hat Enterprise Linux 10; libsss_idmap as a component of Red Hat Enterprise Linux 10; libsss_nss_idmap as a component of Red Hat Enterprise Linux 10; libsss_nss_idmap-devel as a component of Red Hat Enterprise Linux 10; libsss_sudo as a component of Red Hat Enterprise Linux 10; python3-libipa_hbac as a component of Red Hat Enterprise Linux 10; python3-libsss_nss_idmap as a component of Red Hat Enterprise Linux 10; python3-sss as a component of Red Hat Enterprise Linux 10; python3-sss-murmur as a component of Red Hat Enterprise Linux 10; python3-sssdconfig as a component of Red Hat Enterprise Linux 10; sssd as a component of Red Hat Enterprise Linux 10; sssd-ad as a component of Red Hat Enterprise Linux 10; sssd-client as a component of Red Hat Enterprise Linux 10; sssd-common as a component of Red Hat Enterprise Linux 10; sssd-common-pac as a component of Red Hat Enterprise Linux 10; sssd-dbus as a component of Red Hat Enterprise Linux 10; sssd-idp as a component of Red Hat Enterprise Linux 10; sssd-ipa as a component of Red Hat Enterprise Linux 10; sssd-kcm as a component of Red Hat Enterprise Linux 10; sssd-krb5 as a component of Red Hat Enterprise Linux 10; sssd-krb5-common as a component of Red Hat Enterprise Linux 10; sssd-ldap as a component of Red Hat Enterprise Linux 10; sssd-nfs-idmap as a component of Red Hat Enterprise Linux 10; sssd-passkey as a component of Red Hat Enterprise Linux 10; sssd-proxy as a component of Red Hat Enterprise Linux 10; sssd-tools as a component of Red Hat Enterprise Linux 10; sssd-winbind-idmap as a component of Red Hat Enterprise Linux 10; sssd.src as a component of Red Hat Enterprise Linux 10; and 135 more
    After
    libipa_hbac as a component of Red Hat Enterprise Linux 10; libsss_autofs as a component of Red Hat Enterprise Linux 10; libsss_certmap as a component of Red Hat Enterprise Linux 10; libsss_idmap as a component of Red Hat Enterprise Linux 10; libsss_nss_idmap as a component of Red Hat Enterprise Linux 10; libsss_nss_idmap-devel as a component of Red Hat Enterprise Linux 10; libsss_sudo as a component of Red Hat Enterprise Linux 10; python3-libipa_hbac as a component of Red Hat Enterprise Linux 10; python3-libsss_nss_idmap as a component of Red Hat Enterprise Linux 10; python3-sss as a component of Red Hat Enterprise Linux 10; python3-sss-murmur as a component of Red Hat Enterprise Linux 10; python3-sssdconfig as a component of Red Hat Enterprise Linux 10; sssd as a component of Red Hat Enterprise Linux 10; sssd-ad as a component of Red Hat Enterprise Linux 10; sssd-client as a component of Red Hat Enterprise Linux 10; sssd-common as a component of Red Hat Enterprise Linux 10; sssd-common-pac as a component of Red Hat Enterprise Linux 10; sssd-dbus as a component of Red Hat Enterprise Linux 10; sssd-idp as a component of Red Hat Enterprise Linux 10; sssd-ipa as a component of Red Hat Enterprise Linux 10; sssd-kcm as a component of Red Hat Enterprise Linux 10; sssd-krb5 as a component of Red Hat Enterprise Linux 10; sssd-krb5-common as a component of Red Hat Enterprise Linux 10; sssd-ldap as a component of Red Hat Enterprise Linux 10; sssd-nfs-idmap as a component of Red Hat Enterprise Linux 10; sssd-passkey as a component of Red Hat Enterprise Linux 10; sssd-proxy as a component of Red Hat Enterprise Linux 10; sssd-tools as a component of Red Hat Enterprise Linux 10; sssd-winbind-idmap as a component of Red Hat Enterprise Linux 10; sssd.src as a component of Red Hat Enterprise Linux 10; and 136 more
    Red Hat Product Security ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
ENISA EUVD · EUVD-2026-23032↗CVE authority or vendor reference↗Vendor advisory↗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-2026-6245 · cve.blacktree.nl