CVE-2026-46154: Linux kernel · sched_ext: Read scx_root under scx_cgroup_ops_rwsem in cgroup setters
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.0 High · patch available : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 28 May 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@7.0.0-28.28?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws@7.0.0-1008.8?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure@7.0.0-1009.9?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde@7.0.0-1008.8?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp@7.0.0-1008.8?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke@7.0.0-1003.4?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 has been released by Ubuntu in kernel versions 7.0.0-28.28 and later for various kernel flavors. Users should update their Linux kernel packages to the fixed versions listed in the Ubuntu advisories USN-8566-1 and USN-8568-1 and reboot their systems to apply the fixes. Due to an ABI change, recompilation and reinstallation of third-party kernel modules may be required. No additional mitigation steps are indicated by the vendor.
Description
A use-after-free vulnerability in the Linux kernel's scheduler extension (sched_ext) was resolved. The flaw involves reading a stale pointer (scx_root) under the scx_cgroup_ops_rwsem lock in cgroup setter functions, potentially leading to dereferencing freed memory. This can occur if the scheduler is disabled and freed while another is enabled concurrently. The vulnerability affects multiple Linux kernel versions prior to 7.0.0-28.28 and related builds. The issue has been assigned CVE-2026-46154 and carries a CVSS 3.1 score of 7.0, indicating a medium severity. A patch is available and included in updated Linux kernel packages for Ubuntu 26.04 LTS and related variants. Users should apply the updates and reboot to mitigate the risk.
References
- ubuntu.com/security/CVE-2026-46154 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-46154 (opens in a new tab)
- git.kernel.org/linus/80afd4c84bc8f5e80145ce35279f5ce53f6043db (opens in a new tab)
- git.kernel.org/stable/c/0f54f6355575971673d8aac7da107ec4178e45bd (opens in a new tab)
- git.kernel.org/stable/c/80afd4c84bc8f5e80145ce35279f5ce53f6043db (opens in a new tab)
- git.kernel.org/stable/c/ce9aaa3af445c391735c9d000c4db60dfd5640d4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8566-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8568-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8569-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8593-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8603-1 (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)