smb: client: require a full NFS mode SID before reading mode bits
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.
CVE-2026-43350
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-43350
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "e2f8fbfb8d09c06decde162090fac3ee220aa280",
"lessThan": "23b54d6cc3ef30a51d984dc74364f24039ae2ecb",
"versionType": "git"
},
{
"status": "affected",
"version": "e2f8fbfb8d09c06decde162090fac3ee220aa280",
"lessThan": "1592a6cd6f653f2d24572a6976c7a775b19f4940",
"versionType": "git"
},
{
"status": "affected",
"version": "e2f8fbfb8d09c06decde162090fac3ee220aa280",
"lessThan": "8bd4cad3f458d11650d51c2d24b03fb1770ae6cc",
"versionType": "git"
},
{
"status": "affected",
"version": "e2f8fbfb8d09c06decde162090fac3ee220aa280",
"lessThan": "b53b8e98c23310294fc45fc686db5ee860311896",
"versionType": "git"
},
{
"status": "affected",
"version": "e2f8fbfb8d09c06decde162090fac3ee220aa280",
"lessThan": "c8eef12af1cc73031639ea7cf16e0b10e2536b0b",
"versionType": "git"
},
{
"status": "affected",
"version": "e2f8fbfb8d09c06decde162090fac3ee220aa280",
"lessThan": "38a69f08ee82c450d3e4168707fff2e317dc3ff7",
"versionType": "git"
},
{
"status": "affected",
"version": "e2f8fbfb8d09c06decde162090fac3ee220aa280",
"lessThan": "f8488c07bea2431ee12a6067d736578064fa46b4",
"versionType": "git"
},
{
"status": "affected",
"version": "e2f8fbfb8d09c06decde162090fac3ee220aa280",
"lessThan": "2757ad3e4b6f9e0fed4c7739594e702abc5cab21",
"versionType": "git"
}
],
"programFiles": [
"fs/smb/client/cifsacl.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.4"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.4",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.259",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.210",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.175",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.136",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.84",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.25",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.0.2",
"versionType": "semver",
"lessThanOrEqual": "7.0.*"
},
{
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/smb/client/cifsacl.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-43350
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #40063 · Revision 1
- Added to Heist Feed
- Publisher date