CVE-2025-40088: Linux kernel · hfsplus: fix slab-out-of-bounds read in hfsplus_strcasecmp()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.1 High · fixed in 5.15.0-1100.107~20.04.2 : patch Linux kernel soon.
Data as of 28 Oct 2026, 11:18 UTC
- 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:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 30 Oct 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.
Patches and advisories
- 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)
- ubuntu.com/security/notices/USN-8034-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8048-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8033-6 (opens in a new tab)
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 has been released in multiple Linux kernel versions, including 5.15.0-1100.107~20.04.2 and others as listed in the fixedVersions. Users and administrators should update their Linux kernel to one of the fixed versions provided by their distribution, such as those in the Ubuntu security advisory USN-8029-1. No additional mitigation steps are required beyond applying the official kernel updates.
Description
CVE-2025-40088 is a high-severity vulnerability in the Linux kernel's hfsplus filesystem driver. It involves a slab-out-of-bounds read in the hfsplus_strcasecmp() function, which can lead to a kernel memory safety violation. This issue has been fixed in multiple Linux kernel versions. The vulnerability was publicly disclosed with a CVSS score of 7.1 and is addressed in official Ubuntu security updates.
References
- ubuntu.com/security/CVE-2025-40088 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-40088 (opens in a new tab)
- git.kernel.org/linus/42520df65bf67189541a425f7d36b0b3e7bd7844 (opens in a new tab)
- git.kernel.org/stable/c/42520df65bf67189541a425f7d36b0b3e7bd7844 (opens in a new tab)
- git.kernel.org/stable/c/4bc081ba6c52b0c88c92701e3fbc33c7e2277afb (opens in a new tab)
- git.kernel.org/stable/c/4f5ab4a9c6abd8b0d713cc2b7b041bc10d70f241 (opens in a new tab)
- git.kernel.org/stable/c/586c75dfd1d265c4150f6529debb85c9d62e101f (opens in a new tab)
- git.kernel.org/stable/c/603158d4efa98a13a746bd586c20f194f4a31ec8 (opens in a new tab)
- git.kernel.org/stable/c/7ab44236b32ed41eb0636797e8e8e885a2f3b18a (opens in a new tab)
- git.kernel.org/stable/c/b47a75b6f762321f9eb6f31aab7bce47a37063b7 (opens in a new tab)
- git.kernel.org/stable/c/ef250c3edd995d7bb5a5e5122ffad1c28a8686eb (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)