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Full vulnerability report · 2025
CVE-2025-0620High confidence

Samba: smbd doesn't pick up group membership changes when re-authenticating an expired smb session

Unknown · Unknown

4.9MediumCVSS 3.1
Recommended action
Scheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Fix not verified
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-2025-0620 · CSAF 2.0 · revision 3 · finalRed Hat Product Securitysamba: smbd doesn't pick up group membership changes when re-authenticating an expired SMB session
78 known affected

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

  • ldb-tools as a component of Red Hat Enterprise Linux 10
  • libldb as a component of Red Hat Enterprise Linux 10
  • libldb-devel as a component of Red Hat Enterprise Linux 10
  • libnetapi as a component of Red Hat Enterprise Linux 10
  • libnetapi-devel as a component of Red Hat Enterprise Linux 10
  • libsmbclient as a component of Red Hat Enterprise Linux 10
  • libsmbclient-devel as a component of Red Hat Enterprise Linux 10
  • libwbclient as a component of Red Hat Enterprise Linux 10
  • libwbclient-devel as a component of Red Hat Enterprise Linux 10
  • python3-ldb as a component of Red Hat Enterprise Linux 10
  • python3-samba as a component of Red Hat Enterprise Linux 10
  • python3-samba-dc as a component of Red Hat Enterprise Linux 10
Summary
A flaw was found in Samba. The smbd service daemon does not pick up group membership changes when re-authenticating an expired SMB session. This issue can expose file shares until clients disconnect and then connect again.
Remediation
Fix deferred
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-2025-17307

No EUVD known-exploited evidence

A flaw was found in Samba. The smbd service daemon does not pick up group membership changes when re-authenticating an expired SMB session. This issue can expose file shares until clients disconnect and then connect again.

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
4.9 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionScheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Fix not verified
01

What, why and how

A flaw was found in Samba. The smbd service daemon does not pick up group membership changes when re-authenticating an expired SMB session. This issue can expose file shares until clients disconnect and then connect again.

What

A flaw was found in Samba. The smbd service daemon does not pick up group membership changes when re-authenticating an expired SMB session. This issue can expose file shares until clients disconnect and then connect again.

Why

A file or directory that should be restricted can be reached by an external party because its access controls or placement are unsafe.

How

An attacker operating through a network path may attempt exploitation with elevated privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

A flaw was found in Samba. The smbd service daemon does not pick up group membership changes when re-authenticating an expired SMB session. This issue can expose file shares until clients disconnect and then connect again.

Why

A file or directory that should be restricted can be reached by an external party because its access controls or placement are unsafe.

How

An attacker operating through a network path may attempt exploitation with elevated privileges. 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.
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
a network path → Files or Directories Accessible to External Parties → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
High: elevated access 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-552 ↗

CWE-552: Files or Directories Accessible to External Parties. The product makes files or directories accessible to unauthorized actors, even though they should not be.

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:L/PR:H/UI:N/S:U/C:H/I:N/A:N

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.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRHighPrivileges required: The attacker needs elevated or administrative privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.INoneIntegrity impact: No direct loss is represented by this metric.ANoneAvailability impact: No direct loss is represented by this metric.
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.
NetworkCWE-552
A

Official authority intelligence

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

ENISA EUVD · EUVD-2025-17307Official EUVD mapping

A flaw was found in Samba. The smbd service daemon does not pick up group membership changes when re-authenticating an expired SMB session. This issue can expose file shares until clients disconnect and then connect again.

Official EUVD record
BSI · German · WID-SEC-W-2025-1221Samba: Schwachstelle ermöglicht Umgehen von Sicherheitsvorkehrungen

Ein entfernter, authentisierter Angreifer kann eine Schwachstelle in Samba ausnutzen, um Sicherheitsvorkehrungen zu umgehen.

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 not verified
Affected
ldb-tools as a component of Red Hat Enterprise Linux 10; libldb as a component of Red Hat Enterprise Linux 10; libldb-devel as a component of Red Hat Enterprise Linux 10; libnetapi as a component of Red Hat Enterprise Linux 10; libnetapi-devel as a component of Red Hat Enterprise Linux 10; libsmbclient as a component of Red Hat Enterprise Linux 10; libsmbclient-devel as a component of Red Hat Enterprise Linux 10; libwbclient as a component of Red Hat Enterprise Linux 10; libwbclient-devel as a component of Red Hat Enterprise Linux 10; python3-ldb as a component of Red Hat Enterprise Linux 10; python3-samba as a component of Red Hat Enterprise Linux 10; python3-samba-dc as a component of Red Hat Enterprise Linux 10; python3-samba-test as a component of Red Hat Enterprise Linux 10; samba as a component of Red Hat Enterprise Linux 10; samba-client as a component of Red Hat Enterprise Linux 10; samba-client-libs as a component of Red Hat Enterprise Linux 10; samba-common as a component of Red Hat Enterprise Linux 10; samba-common-libs as a component of Red Hat Enterprise Linux 10; samba-common-tools as a component of Red Hat Enterprise Linux 10; samba-dc-libs as a component of Red Hat Enterprise Linux 10; samba-dcerpc as a component of Red Hat Enterprise Linux 10; samba-devel as a component of Red Hat Enterprise Linux 10; samba-gpupdate as a component of Red Hat Enterprise Linux 10; samba-krb5-printing as a component of Red Hat Enterprise Linux 10; samba-ldb-ldap-modules as a component of Red Hat Enterprise Linux 10; samba-libs as a component of Red Hat Enterprise Linux 10; samba-pidl as a component of Red Hat Enterprise Linux 10; samba-test as a component of Red Hat Enterprise Linux 10; samba-test-libs as a component of Red Hat Enterprise Linux 10; samba-tools as a component of Red Hat Enterprise Linux 10; and 48 more
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 6 Jun 2025 · Last source change 31 Aug 2026, 11:28 UTC · CWE-552 · Files or Directories Accessible to External Parties

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-2025-17307
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD modified after enrichment

Missing structured fields: affected product. Missing data is not evidence of low risk; review the primary advisory.

Material change intelligence

What changed after publication

View recent updates →

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
ENISA EUVD · EUVD-2025-17307↗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-2025-0620 · cve.blacktree.nl