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VulnerabilityPublished Updated

CVE-2025-40244: Linux kernel · hfsplus: fix KMSAN uninit-value issue in __hfsplus_ext_cache_extent()

Affects Linux kernelSource GCVE Database

0

Not known to be exploited · CVSS 7.8 High · fixed in 6.12.0 : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 6.12.0
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 4 Dec 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Affected software

ProductAffectedFixed in
Red Hatredhat/kernelpkg:rpm/redhat/kernelOther threatsAffected
  • =6.12.0-rc5
Fixed in–

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AI-suggested

A fix for this vulnerability has been implemented in Linux kernel versions after 6.12.0-rc5. Users and administrators should update to a kernel version that includes this fix to mitigate the issue. Since this is a kernel-level flaw, applying the official kernel patch or upgrading to a fixed kernel release is the recommended remediation. Patch status is not explicitly confirmed in the input data; check the vendor advisory for current remediation guidance.

Description

A high severity vulnerability (CVE-2025-40244) in the Linux kernel's HFS+ filesystem driver was identified and resolved. The issue involved an uninitialized value detected by Kernel Memory Sanitizer (KMSAN) in the __hfsplus_ext_cache_extent() function, which could lead to kernel panic and potentially allow an attacker with local privileges to cause denial of service or escalate privileges. The vulnerability was reported by syzbot and fixed in kernel versions after 6.12.0-rc5. No known exploits are reported in the wild.

References

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