CVE-2026-97443: Linux kernel · perf/ftrace: Fix WARNING in __unregister_ftrace_function
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 26 Oct 2026, 12:55 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 24 Sep 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
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 fix is available that adds a check for the FTRACE_OPS_FL_ENABLED flag before attempting to unregister the ftrace function. Users should apply the official kernel update that includes this fix to prevent the warning and ensure proper cleanup. No additional mitigation steps are indicated.
Description
A vulnerability in the Linux kernel's perf/ftrace subsystem caused a warning (WARN_ON) due to an unconditional call to unregister a function that may not have been registered. This issue occurs during error cleanup in perf_event_alloc() when unregistering an ftrace function that was never enabled. The fix involves checking if the function was enabled before attempting to unregister it.
References
- ubuntu.com/security/CVE-2026-97443 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-97443 (opens in a new tab)
- git.kernel.org/stable/c/7f845820afaad339341c2ae42bc7fdec175df9ea (opens in a new tab)
- git.kernel.org/stable/c/df097713b56ffac5eed32a9be2e7d27ac48d9087 (opens in a new tab)
- git.kernel.org/stable/c/9581123304b23049437324038698af9fb56ee663 (opens in a new tab)