CVE-2026-64512: Linux kernel · ACPI: CPPC: Suppress UBSAN warning caused by field misuse
Affects Linux kernelSource GCVE Database
Not known to be exploited · fixed in 5.15.0-1117.124~20.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 13:47 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +43
Exploitation evidence
Disclosed: evidence found.
CVE published 25 Jul 2026
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 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther 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 confirms that this issue has been fixed in updated kernel releases. Users should update to the fixed versions to resolve this vulnerability.
Description
A vulnerability in the Linux kernel's ACPI CPPC driver caused a UBSAN (Undefined Behavior Sanitizer) warning due to misuse of the access_width field depending on the reg->space_id type. This issue could lead to a shift-out-of-bounds error when the access_width value is greater than 4. The problem has been resolved by validating the region type and access_width value, and adjusting the code accordingly.
References
- ubuntu.com/security/CVE-2026-64512 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64512 (opens in a new tab)
- git.kernel.org/linus/1b1acf2dada0cc3931bb2cb9ff8832edfbee46a1 (opens in a new tab)
- git.kernel.org/stable/c/1b1acf2dada0cc3931bb2cb9ff8832edfbee46a1 (opens in a new tab)
- git.kernel.org/stable/c/2fb80e962029000959f651665baa4838cc92eb99 (opens in a new tab)
- git.kernel.org/stable/c/37f28bf8f14672dfa395994e41fd778a63f0bf5c (opens in a new tab)
- git.kernel.org/stable/c/b54c4632946ae42f2b39ed38abd909bbf78cbcc2 (opens in a new tab)
- git.kernel.org/stable/c/dc066bd13c860bb27d6ace511210e18b8064c1d9 (opens in a new tab)
- git.kernel.org/stable/c/e904596ba6dd108534ffa15e3e46b2fe245145e2 (opens in a new tab)
- git.kernel.org/stable/c/f29dc6132d4968e39d8fa575d1a12e2c718ce57b (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8727-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8800-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-4 (opens in a new tab)