CVE-2026-64380

Medium

Elevated severity or exploit probability.

CVSS base

8.2 HIGH

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

EPSS — probability of exploitation (30 days)

0.4%

37.9th percentile

CISA KEV

Not listed

Weakness / dates

—

Published 2026-07-25 · modified 2026-09-08

CVSS breakdown

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

Attack Vector	N	Network
Attack Complexity	L	Low
Privileges Required	N	None
User Interaction	N	None
Scope	U	Unchanged
Confidentiality	L	Low
Integrity	N	None
Availability	H	High

Timeline

2026-07-25 — Published (NVD)
2026-09-08 — Last modified (NVD)

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.

Affected

linux

References

Official: NVD · CVE.org