🛡️ CVE-2025-40348 — kernel

⚪ Unknown ✅ No Known Exploit NVD
N/A
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

slab: Avoid race on slab->obj_exts in alloc_slab_obj_exts

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

slab: Avoid race on slab->obj_exts in alloc_slab_obj_exts

If two competing threads enter alloc_slab_obj_exts() and one of them

fails to allocate the object extension vector, it might override the

valid slab->obj_exts allocated by the other thread with

OBJEXTS_ALLOC_FAIL. This will cause the thread that lost this race and

expects a valid pointer to dereference a NULL pointer later on.

Update slab->obj_exts atomically using cmpxchg() to avoid

slab->obj_exts overrides by racing threads.

Thanks for Vlastimil and Suren's help with debugging.

Affected software

CVE-2025-40348 is recorded against 2 packages.

  • kernel (from 6.17.4 up to 6.17.6)
  • unknown

Timeline and source

Published on 16 December 2025 and last revised on 15 July 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.

References

git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
github.com (Advisory)
nvd.nist.gov (Advisory)
git.kernel.org (Package)

CVE-2025-40348 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity Unknown
CVSS Score N/A
CVSS Vector N/A
CWE N/A
Public Exploit ✅ No
Source NVD
Published 2025-12-16
Updated 2026-08-12
Modified 2026-07-15
Fix URL N/A

Affected Packages

Software From version Fixed in
kernel 6.17.4 6.17.6
unknown — —

Similar Threats

Free Vulnerability Check

Is your site affected by CVE-2025-40348?

BotEraser helps you identify potentially vulnerable plugins and themes by checking your installation against CVE-2025-40348 and other known CVE records.

Scan My Site Free →

No credit card required  ·  Results in minutes

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.