CVE-2025-40081: Linux kernel · perf: arm_spe: Prevent overflow in PERF_IDX2OFF()
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 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, 5.15.0-1100.109~20.04.1 +71
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 28 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 should be applied by upgrading to one of the fixed linux-azure kernel versions listed (e.g., 5.15.0-1100.107~20.04.2 or later). The vendor advisory from Ubuntu confirms the availability of fixes. No additional mitigation steps are indicated beyond applying the official updates.
Description
A vulnerability in the Linux kernel's perf subsystem for ARM SPE was fixed by preventing an overflow in the PERF_IDX2OFF() macro. The issue involved improper casting of nr_pages, which could cause overflow when handling large AUX buffer sizes of 2 GiB or more. This flaw was addressed by casting nr_pages to unsigned long. Multiple versions of the linux-azure kernel prior to specific fixed releases are affected. The vulnerability has a high severity score and could allow an attacker with local privileges to compromise system confidentiality, integrity, and availability.
References
- ubuntu.com/security/CVE-2025-40081 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-40081 (opens in a new tab)
- git.kernel.org/linus/a29fea30dd93da16652930162b177941abd8c75e (opens in a new tab)
- git.kernel.org/stable/c/1a19ba8e1f4ff24ece8ca69b79df8442c431db90 (opens in a new tab)
- git.kernel.org/stable/c/379cae2cb982f571cda9493ac573ab71125fd299 (opens in a new tab)
- git.kernel.org/stable/c/5d01f2b81568289443d22f1e13a363f829de6343 (opens in a new tab)
- git.kernel.org/stable/c/7500384d3c9587593d75ded3b006835e7aa73ef8 (opens in a new tab)
- git.kernel.org/stable/c/a29fea30dd93da16652930162b177941abd8c75e (opens in a new tab)
- git.kernel.org/stable/c/e516cfd19b0f4c774a57b17fb43a7f41991f0735 (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)
- ubuntu.com/security/notices/USN-8034-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8048-1 (opens in a new tab)