CVE-2026-43350

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.

CVSS v3 7.6 HIGH

7.6^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.8 / Impact : 4.7

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://git.kernel.org/stable/c/1592a6cd6f653f2d24572a6976c7a775b19f4940
https://git.kernel.org/stable/c/23b54d6cc3ef30a51d984dc74364f24039ae2ecb
https://git.kernel.org/stable/c/2757ad3e4b6f9e0fed4c7739594e702abc5cab21	Patch
https://git.kernel.org/stable/c/38a69f08ee82c450d3e4168707fff2e317dc3ff7	Patch
https://git.kernel.org/stable/c/8bd4cad3f458d11650d51c2d24b03fb1770ae6cc
https://git.kernel.org/stable/c/b53b8e98c23310294fc45fc686db5ee860311896	Patch
https://git.kernel.org/stable/c/c8eef12af1cc73031639ea7cf16e0b10e2536b0b	Patch
https://git.kernel.org/stable/c/f8488c07bea2431ee12a6067d736578064fa46b4	Patch

Configurations

Configuration 1 (hide)

OR	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::

History

No history.

Information

Published : 2026-05-08 14:16

Updated : 2026-06-19 13:16

NVD link : CVE-2026-43350

Mitre link : CVE-2026-43350

CVE.ORG link : CVE-2026-43350

JSON object : View

Products Affected

linux

linux_kernel

CWE

NVD-CWE-noinfo

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three subauthorities, but compare_sids()\nonly compares min(a, b) subauthorities. A malicious server can return\nan ACE with num_subauth = 2 and sub_auth[] = {88, 3}, which still\nmatches sid_unix_NFS_mode and then drives the sub_auth[2] read four\nbytes past the end of the ACE.\n\nRequire num_subauth >= 3 before treating the ACE as an NFS mode SID.\nThis keeps the fix local to the special-SID mode path without changing\ncompare_sids() semantics for the rest of cifsacl."}], "lastModified": "2026-06-19T13:16:29.943", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "69577FD5-601B-4A4B-BBA2-0FC336EB0D3E", "versionEndExcluding": "6.6.136", "versionStartIncluding": "5.4"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "D4ECA0DE-AFF5-4688-B219-4CA2336CA5B7", "versionEndExcluding": "6.12.84", "versionStartIncluding": "6.7"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "8B0A7E0E-F6D8-45DB-8CD9-01839FE40A6C", "versionEndExcluding": "6.18.25", "versionStartIncluding": "6.13"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "1BD58F1E-7C20-4C0D-92A2-FAC5CBFBE8A8", "versionEndExcluding": "7.0.2", "versionStartIncluding": "6.19"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}