CVE-2026-64530: Linux kernel · net/sched: cls_api: Handle TC_ACT_CONSUMED in tcf_qevent_handle
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical · fixed in 5.15.0-1117.124~20.04.1 : patch Linux kernel as a priority.
Data as of 28 Oct 2026, 05:11 UTC
- EPSS
- 0.6% chance of exploitation in 30 days – higher than 51% 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 +57
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 26 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
- ubuntu.com/security/notices/USN-8781-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8876-1 (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-8888-2 (opens in a new tab)
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 has been released in multiple Linux kernel versions 5.15.0-1117.124~20.04.1 and later. Users and administrators should update affected Linux kernel packages to these fixed versions or later to remediate the vulnerability. No additional mitigation steps are required beyond applying the official kernel updates.
Description
CVE-2026-64530 is a critical use-after-free vulnerability in the Linux kernel's network scheduler (net/sched) subsystem. The flaw occurs because the function tcf_qevent_handle() does not properly handle the TC_ACT_CONSUMED return code from tcf_classify(), leading to the kernel operating on a socket buffer (skb) that it no longer owns. This can cause a use-after-free condition when enqueueing, dropping, or updating statistics on the skb. The issue affects certain Linux kernel versions prior to 5.15.0-1117.124~20.04.1 and related builds. A fix has been released in multiple 5.15.0 kernel versions.
References
- ubuntu.com/security/CVE-2026-64530 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64530 (opens in a new tab)
- git.kernel.org/linus/a8a02897f2b479127db261de05cbf0c28b98d159 (opens in a new tab)
- git.kernel.org/stable/c/2140c2f3f2e7b066e1ae616ede8856cafd8015e9 (opens in a new tab)
- git.kernel.org/stable/c/447d493034a9cf7bf13a2abac86d0573d907ec2f (opens in a new tab)
- git.kernel.org/stable/c/5ed3d6f85991656667059d3fa5a1d683ac58c447 (opens in a new tab)
- git.kernel.org/stable/c/a8a02897f2b479127db261de05cbf0c28b98d159 (opens in a new tab)
- git.kernel.org/stable/c/e1270e69dcf2c3512c453484178f2e9dc0db3f05 (opens in a new tab)
- git.kernel.org/stable/c/e28aedab9488343924d227b5a896faed67ce84d5 (opens in a new tab)
- git.kernel.org/stable/c/f42e8134a3a1074b834a574d404352f867ba994a (opens in a new tab)
- ubuntu.com/security/notices/USN-8781-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8816-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8876-1 (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)