In the Linux kernel, the following vulnerability has been resolved:

smb: client: require a full NFS mode SID before reading mode bits

parse_dacl() treats an ACE SID matching sid_unix_NFS_mode as an NFS
mode SID and reads sid.sub_auth[2] to recover the mode bits.

That assumes the ACE carries three subauthorities, but compare_sids()
only compares min(a, b) subauthorities. A malicious server can return
an ACE with num_subauth = 2 and sub_auth[] = {88, 3}, which still
matches sid_unix_NFS_mode and then drives the sub_auth[2] read four
bytes past the end of the ACE.

Require num_subauth >= 3 before treating the ACE as an NFS mode SID.
This keeps the fix local to the special-SID mode path without changing
compare_sids() semantics for the rest of cifsacl.

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-4664-1 linux security update
Debian DLA Debian DLA DLA-4665-1 linux security update
Debian DLA Debian DLA DLA-4671-1 linux-6.1 security update
Ubuntu USN Ubuntu USN USN-8488-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8488-2 Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN Ubuntu USN USN-8507-1 Linux kernel (NVIDIA) vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 19 Jun 2026 12:45:00 +0000


Mon, 01 Jun 2026 17:00:00 +0000


Fri, 15 May 2026 21:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-119
CWE-125

Fri, 15 May 2026 19:30:00 +0000

Type Values Removed Values Added
Weaknesses NVD-CWE-noinfo

Mon, 11 May 2026 09:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-119
CWE-125

Mon, 11 May 2026 07:45:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

cvssV3_1

{'score': 7.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H'}


Sat, 09 May 2026 02:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-125
CWE-129

Sat, 09 May 2026 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Moderate


Fri, 08 May 2026 18:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-125
CWE-129

Fri, 08 May 2026 14:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: smb: client: require a full NFS mode SID before reading mode bits parse_dacl() treats an ACE SID matching sid_unix_NFS_mode as an NFS mode SID and reads sid.sub_auth[2] to recover the mode bits. That assumes the ACE carries three subauthorities, but compare_sids() only compares min(a, b) subauthorities. A malicious server can return an ACE with num_subauth = 2 and sub_auth[] = {88, 3}, which still matches sid_unix_NFS_mode and then drives the sub_auth[2] read four bytes past the end of the ACE. Require num_subauth >= 3 before treating the ACE as an NFS mode SID. This keeps the fix local to the special-SID mode path without changing compare_sids() semantics for the rest of cifsacl.
Title smb: client: require a full NFS mode SID before reading mode bits
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-06-19T11:58:33.078Z

Reserved: 2026-05-01T14:12:56.003Z

Link: CVE-2026-43350

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Modified

Published: 2026-05-08T14:16:45.123

Modified: 2026-06-17T10:49:26.023

Link: CVE-2026-43350

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-05-08T00:00:00Z

Links: CVE-2026-43350 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-05-15T22:30:06Z

Weaknesses