CVE-2026-80626: Linux kernel · powerpc/perf: fix preempt count underflow in fsl_emb_pmu_del
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.7 Medium · fixed in 5.15.0-1117.124~20.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 12% 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 +40
CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 28 Aug 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 to correct the improper handling of preempt count in the powerpc/perf subsystem. Updating to patched kernel versions resolves the issue. No additional mitigations are indicated by the vendor advisory.
Description
A vulnerability in the Linux kernel's powerpc/perf subsystem caused a preempt count underflow due to improper pairing of get_cpu_var() and put_cpu_var() calls in the fsl_emb_pmu_del() function. This underflow can lead to a 'scheduling while atomic' kernel BUG on preemptible kernels. The issue has been fixed by correctly bracketing the percpu access calls. Multiple specific Linux kernel versions are affected. A patch is available to address this flaw.
References
- nvd.nist.gov/vuln/detail/CVE-2026-80626 (opens in a new tab)
- git.kernel.org/stable/c/5397142d60aa29dcf636f5459d960bfc4f97c42a (opens in a new tab)
- git.kernel.org/stable/c/67aeb1eb93d4ffd898a3e74a7f3fe46ee71feb28 (opens in a new tab)
- git.kernel.org/stable/c/73711688479df333acc134e3730fff1acba1843e (opens in a new tab)
- git.kernel.org/stable/c/81e3a86030462824a67d697739cf3f387f4ba350 (opens in a new tab)
- git.kernel.org/stable/c/9a515e00b00132b6fc3f1dd62dc5204bbda8cb10 (opens in a new tab)
- git.kernel.org/stable/c/b504fd953664c3f4d176ae8cb594adb3fda9d577 (opens in a new tab)
- git.kernel.org/stable/c/b89477077c834d94381c7bf07d81193bebefcff9 (opens in a new tab)
- git.kernel.org/stable/c/c0c7722308c5f303117d8bd555290fdf26b098da (opens in a new tab)
- ubuntu.com/security/CVE-2026-80626 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-80626 (opens in a new tab)
- git.kernel.org/linus/81e3a86030462824a67d697739cf3f387f4ba350 (opens in a new tab)
- ubuntu.com/security/notices/USN-8878-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8877-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8889-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-2 (opens in a new tab)