Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: smb: client: harden POSIX SID length parsing posix_info_sid_size() reads sid[1] to obtain the subauthority count, but its existing boundary check still accepts buffers with only one remaining byte. Require two bytes before reading sid[1] so all client paths that reuse the helper reject truncated POSIX SIDs safely.
CVSS Score
HIGH
References
- https://git.kernel.org/stable/c/0de5b8e76847f5de26f364a82c6602c4881c30da
- https://git.kernel.org/stable/c/171605aed68380c2fa75dff9b3a1ed427c50065b
- https://git.kernel.org/stable/c/4213c1208978483021d7d125c131de3985d38f61
- https://git.kernel.org/stable/c/427eb7eb46425fec845a43e861f3d6e2899cae59
- https://git.kernel.org/stable/c/46a84715a015cb48e1b9c219dc88c03d8a541ea4
- https://git.kernel.org/stable/c/7ad2bcf2441430bb2e918fb3ef9a90d775a6e422
- https://git.kernel.org/stable/c/86c5d470f5d42e61123b2f4b4f0b91f4eee5b980
- https://git.kernel.org/stable/c/96e889bc1e759c83f25093e8c2f3da31b4973f30
FAQ
What is CVE-2026-64380?
CVE-2026-64380 is a vulnerability with a CVSS score of 8.2 (HIGH). In the Linux kernel, the following vulnerability has been resolved: smb: client: harden POSIX SID length parsing posix_info_sid_size() reads sid[1] to obtain the subauthority count, but its existing...
How severe is CVE-2026-64380?
CVE-2026-64380 has been rated HIGH with a CVSS base score of 8.2/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-64380?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.