CVE-2026-64380
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.44%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 3.1
- 8.2 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
- EPSS
- 0.44% probability · 37th percentile
- CISA KEV
- Not listed
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/0de5b8e76847f5de26f364a82c6602c4881c30daPatch
- https://git.kernel.org/stable/c/171605aed68380c2fa75dff9b3a1ed427c50065bPatch
- https://git.kernel.org/stable/c/4213c1208978483021d7d125c131de3985d38f61Patch
- https://git.kernel.org/stable/c/427eb7eb46425fec845a43e861f3d6e2899cae59Patch
- https://git.kernel.org/stable/c/46a84715a015cb48e1b9c219dc88c03d8a541ea4Patch
- https://git.kernel.org/stable/c/7ad2bcf2441430bb2e918fb3ef9a90d775a6e422Patch
- https://git.kernel.org/stable/c/86c5d470f5d42e61123b2f4b4f0b91f4eee5b980Patch
- https://git.kernel.org/stable/c/96e889bc1e759c83f25093e8c2f3da31b4973f30Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.