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Fencer Vulns
high 8.8

CVE-2025-22039 json

ksmbd: fix overflow in dacloffset bounds check

published 2025-04-16 18 mo ago modified 2026-09-14 56 d ago also EUVD-2025-11246

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.8%
EPSS 0.8% chance of exploitation in 30 days, percentile 56%
public exploits
0
none known

Summary

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

ksmbd: fix overflow in dacloffset bounds check

The dacloffset field was originally typed as int and used in an unchecked addition, which could overflow and bypass the existing bounds check in both smb_check_perm_dacl() and smb_inherit_dacl().

This could result in out-of-bounds memory access and a kernel crash when dereferencing the DACL pointer.

This patch converts dacloffset to unsigned int and uses check_add_overflow() to validate access to the DACL.

Patch / fix

  • Linux Linux 5.15.221, 6.1.188, 6.6.157, 6.12.23, 6.13.11, 6.14.2, 6.15
  • linux Debian 12 6.1.190-1
  • linux Debian 14, Debian 13 6.12.25-1

debian advisories DEBIAN-CVE-2025-22039

  • linux Ubuntu 22.04 LTS 5.15.0-202.212
  • linux Ubuntu 24.04 LTS 6.8.0-86.87
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1119.126
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1041.43
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1120.130
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1042.45
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1115.121
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1038.43

ubuntu advisories UBUNTU-CVE-2025-22039

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

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-2025-22039 updated

kernel: ksmbd: fix overflow in dacloffset bounds check

  • 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 kernel
    not 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

0.79% chance of exploitation in the next 30 days, higher than 56% 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
NVD 3.1 7.1 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

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.