CVE-2026-64380

high

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.

References

https://git.kernel.org/stable/c/96e889bc1e759c83f25093e8c2f3da31b4973f30

https://git.kernel.org/stable/c/86c5d470f5d42e61123b2f4b4f0b91f4eee5b980

https://git.kernel.org/stable/c/7ad2bcf2441430bb2e918fb3ef9a90d775a6e422

https://git.kernel.org/stable/c/46a84715a015cb48e1b9c219dc88c03d8a541ea4

https://git.kernel.org/stable/c/427eb7eb46425fec845a43e861f3d6e2899cae59

https://git.kernel.org/stable/c/4213c1208978483021d7d125c131de3985d38f61

https://git.kernel.org/stable/c/171605aed68380c2fa75dff9b3a1ed427c50065b

https://git.kernel.org/stable/c/0de5b8e76847f5de26f364a82c6602c4881c30da

Details

Source: Mitre, NVD

Published: 2026-07-25

Updated: 2026-07-25

Risk Information

CVSS v2

Base Score: 5.6

Vector: CVSS2#AV:L/AC:L/Au:N/C:P/I:N/A:C

Severity: Medium

CVSS v3

Base Score: 7.1

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Severity: High

EPSS

EPSS: 0.0022