CVE-2025-40349: Linux kernel · hfs: validate record offset in hfsplus_bmap_alloc
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 5.15.0-1100.107~20.04.2 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 UTC
- 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 5.15.0-1100.107~20.04.2, 5.15.0-1110.119~20.04.1, 5.15.0-1114.123~20.04.1 +72
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 16 Dec 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available and should be applied to affected Linux kernel versions. The vendor advisory from Ubuntu confirms that this issue has been fixed in updated kernel releases. Users should update their Linux kernel to the fixed versions to mitigate this vulnerability. No additional mitigations are required beyond applying the official fix.
Description
A vulnerability in the Linux kernel's HFS+ filesystem implementation (hfsplus_bmap_alloc) could cause a crash due to out-of-bounds memory access when record offsets or lengths exceed node size. This issue has been fixed by adding validation checks on the offset and length values before use, preventing invalid memory access. The flaw affects certain Linux kernel versions prior to specific patched releases. A patch is available and has been incorporated in updated kernel versions.
References
- ubuntu.com/security/CVE-2025-40349 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-40349 (opens in a new tab)
- git.kernel.org/linus/738d5a51864ed8d7a68600b8c0c63fe6fe5c4f20 (opens in a new tab)
- git.kernel.org/stable/c/0058d20d76182861dbdd8fd6e2dd8d18d6d3becf (opens in a new tab)
- git.kernel.org/stable/c/068a46df3e6acc68fb9db0a6313ab379a11ecd6f (opens in a new tab)
- git.kernel.org/stable/c/17ed51cfce6c62cffb97059ef392ad2e0245806e (opens in a new tab)
- git.kernel.org/stable/c/40dfe7a4215a1f20842561ffaf5a6f83a987e75b (opens in a new tab)
- git.kernel.org/stable/c/418e48cab99c52c1760636a4dbe464bf6db2018b (opens in a new tab)
- git.kernel.org/stable/c/4f40a2b3969daf10dca4dea6f6dd0e813f79b227 (opens in a new tab)
- git.kernel.org/stable/c/738d5a51864ed8d7a68600b8c0c63fe6fe5c4f20 (opens in a new tab)
- git.kernel.org/stable/c/f7d9f600c7c3ff5dab36181a388af55f2c95604c (opens in a new tab)
- ubuntu.com/security/notices/USN-8029-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8030-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8034-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8029-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-5 (opens in a new tab)