CVE-2026-64226: Linux kernel · sched_ext: Avoid UAF in scx_root_enable_workfn() init failure path
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 7.0.0-28.28~24.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 12:55 UTC
- 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 7.0.0-28.28~24.04.1, 7.0.0-28.28, 7.0.0-1009.9 +5
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 27 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.
Patches and advisories
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 promptly. The vendor advisory from Ubuntu confirms that this issue has been fixed in updated Linux kernel packages. Users should update to the fixed kernel versions as provided by their distribution. No additional mitigation steps are indicated beyond applying the official fix.
Description
A use-after-free (UAF) vulnerability was identified and resolved in the Linux kernel's sched_ext subsystem, specifically in the scx_root_enable_workfn() function. The flaw occurs because put_task_struct(p) is called before scx_error() dereferences p->comm and p->pid, potentially leading to a UAF if the task's reference count drops to zero. This could allow local attackers to cause memory corruption. The vulnerability has a CVSS score of 7.8 and is considered medium severity. Multiple Linux kernel versions are affected, and patches are available to address the issue.
References
- ubuntu.com/security/CVE-2026-64226 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64226 (opens in a new tab)
- git.kernel.org/linus/9a415cc53711f2238e0f0ca8a6bcc796c003b127 (opens in a new tab)
- git.kernel.org/stable/c/45c7c4e3db8b700307313c035ea08be829a7f21b (opens in a new tab)
- git.kernel.org/stable/c/57e19ba3f58a67eb924022a5a60b67fd08e5cbbd (opens in a new tab)
- git.kernel.org/stable/c/9a415cc53711f2238e0f0ca8a6bcc796c003b127 (opens in a new tab)
- git.kernel.org/stable/c/cf396941901858b0de426cdcd3974eea6a02c98c (opens in a new tab)
- ubuntu.com/security/notices/USN-8618-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8663-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8664-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)