In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate SID in parent security descriptor during ACL inheritance… (CVE-2026-64138)
In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate SID in parent security descriptor during ACL inheritance Introduce smb_validate_ntsd_sid() helper to safely validate Owner SID and Group SID inside the NT Security Descriptor (smb_ntsd) retrieved from the parent directory.
AI Analysis
Technical Summary
The Linux kernel vulnerability identified as CVE-2026-64138 concerns the ksmbd module's handling of Security Identifiers (SIDs) during ACL inheritance. The issue was addressed by introducing the smb_validate_ntsd_sid() helper function, which ensures safe validation of Owner SID and Group SID within the NT Security Descriptor (smb_ntsd) obtained from the parent directory. This mitigates potential risks arising from improper SID validation in the inheritance process.
Potential Impact
The vulnerability could have allowed improper handling of security descriptors during ACL inheritance in the ksmbd kernel module, potentially leading to incorrect permission assignments or security descriptor corruption. However, no known exploits in the wild have been reported, and the exact impact severity is not detailed in the available data.
Mitigation Recommendations
A fix has been implemented in the Linux kernel to address this vulnerability by adding the smb_validate_ntsd_sid() function. Users should apply the official Linux kernel updates that include this patch to remediate the issue. Since no specific patch links or affected versions are provided, users should consult their Linux distribution's security advisories for the relevant kernel update.
In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate SID in parent security descriptor during ACL inheritance… (CVE-2026-64138)
Description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate SID in parent security descriptor during ACL inheritance Introduce smb_validate_ntsd_sid() helper to safely validate Owner SID and Group SID inside the NT Security Descriptor (smb_ntsd) retrieved from the parent directory.
CVSS v3.1
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel vulnerability identified as CVE-2026-64138 concerns the ksmbd module's handling of Security Identifiers (SIDs) during ACL inheritance. The issue was addressed by introducing the smb_validate_ntsd_sid() helper function, which ensures safe validation of Owner SID and Group SID within the NT Security Descriptor (smb_ntsd) obtained from the parent directory. This mitigates potential risks arising from improper SID validation in the inheritance process.
Potential Impact
The vulnerability could have allowed improper handling of security descriptors during ACL inheritance in the ksmbd kernel module, potentially leading to incorrect permission assignments or security descriptor corruption. However, no known exploits in the wild have been reported, and the exact impact severity is not detailed in the available data.
Mitigation Recommendations
A fix has been implemented in the Linux kernel to address this vulnerability by adding the smb_validate_ntsd_sid() function. Users should apply the official Linux kernel updates that include this patch to remediate the issue. Since no specific patch links or affected versions are provided, users should consult their Linux distribution's security advisories for the relevant kernel update.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-23jx-58r9-pwv6
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-64138"]
- Ecosystems
- []
- Database Specific Severity
- null
- Cvss Version
- null
Threat ID: 6a5d27a82a4a8d598912b244
Added to database: 07/19/2026, 19:38:16 UTC
Last enriched: 07/19/2026, 19:47:01 UTC
Last updated: 07/20/2026, 19:41:21 UTC
Views: 16
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