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.
Analysis and contextual insights are available on OpenCVE Cloud.
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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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
|
cvssV3_1
|
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
|
cvssV3_1
|
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 |
|
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-05-11T22:22:52.597Z
Reserved: 2026-05-01T14:12:56.003Z
Link: CVE-2026-43350
No data.
Status : Analyzed
Published: 2026-05-08T14:16:45.123
Modified: 2026-05-15T19:29:35.360
Link: CVE-2026-43350
OpenCVE Enrichment
Updated: 2026-05-15T21:00:09Z