CVE-2026-64138 json
ksmbd: validate SID in parent security descriptor during ACL inheritance
published 2026-07-19 3 mo ago modified 2026-10-30 9 d ago also EUVD-2026-45823
- cvss
- 8.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 39%
- public exploits
- 0
- none known
Summary
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: validate SID in parent security descriptor during ACL inheritance
Introduce smb_validate_ntsd_sid() helper to safely validate Owner SID and Group SID inside the NT Security Descriptor (smb_ntsd) retrieved from the parent directory.
Patch / fix
- Linux Linux 6.1.191, 6.6.160, 6.12.92, 6.18.34, 7.0.11, 7.1
- linux Debian 13 6.12.94-1
- linux Debian 14 7.0.12-1
debian advisories DEBIAN-CVE-2026-64138
- linux Ubuntu 24.04 LTS 6.8.0-139.139
- linux Ubuntu 26.04 LTS 7.0.0-28.28
- linux-aws Ubuntu 24.04 LTS 6.8.0-1064.67
- linux-aws Ubuntu 26.04 LTS 7.0.0-1009.9
- linux-gcp Ubuntu 24.04 LTS 6.8.0-1067.75
- linux-gcp Ubuntu 26.04 LTS 7.0.0-1008.8
- linux-gke Ubuntu 24.04 LTS 6.8.0-1062.70
- linux-gke Ubuntu 26.04 LTS 7.0.0-1003.4
ubuntu advisories UBUNTU-CVE-2026-64138
Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0
- git.kernel.org/stable/c/f7c4dee323d9176b8d3f5c69018ee57ae0d4653c commit
- git.kernel.org/stable/c/8efbea0253b7fa2d1960cab0fed36544ca0b41ab commit
- git.kernel.org/stable/c/f0e5c9c663badc9982e6941322eef1cb17de0f11 commit
- git.kernel.org/stable/c/18d8db24b0a5b7be4829238dd4022236df02d421 commit
- git.kernel.org/stable/c/1c9d0646a9959752f11ca1080dc1ff26bd1756cb commit
- git.kernel.org/stable/c/69f030cf95488ae1186c72ac8c66fd279664ea7f commit
Vendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2026-64138 updated
kernel: ksmbd: validate SID in parent security descriptor during ACL inheritance
-
Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernelnot affected: vulnerable code not present
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
Exploit prediction
0.45% chance of exploitation in the next 30 days, higher than 39% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Affected products
- Linux Linux
Classification
- Technology feeds
References
- git.kernel.org /stable/c/f7c4dee323d9176b8d3f5c69018ee57ae0d4653c
- git.kernel.org /stable/c/8efbea0253b7fa2d1960cab0fed36544ca0b41ab
-
git.kernel.org
/stable/c/f0e5c9c663badc9982e6941322eef1cb17de0f11
patch
-
git.kernel.org
/stable/c/18d8db24b0a5b7be4829238dd4022236df02d421
patch
-
git.kernel.org
/stable/c/1c9d0646a9959752f11ca1080dc1ff26bd1756cb
patch
-
git.kernel.org
/stable/c/69f030cf95488ae1186c72ac8c66fd279664ea7f
patch
Sources
- CVE List CVE-2026-64138
- NVD CVE-2026-64138
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.