CVE-2026-64459: Linux kernel · tcp: restore RCU grace period in tcp_ao_destroy_sock
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical · fixed in 7.0.0-1012.12~24.04.1 : patch Linux kernel as a priority.
Data as of 9 Nov 2026, 15:33 UTC
Thin evidence
One scorer or none| CNA (Linux) | CVSS 3.1 | 9.8 |
|---|
- Patch
- Available – fixed in 7.0.0-1012.12~24.04.1, 7.0.0-1014.14~24.04.1, 7.0.0-1013.13~24.04.1 +14
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 25 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 9 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-8726-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8727-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8800-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-3 (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 fix is available and has been applied in Linux kernel versions 7.0.0-31.31~24.04.1 and later. Users should upgrade to these fixed kernel versions as provided by their Linux distribution. No additional mitigation is required once the kernel is updated.
Description
A critical use-after-free vulnerability in the Linux kernel's TCP Authentication Option (TCP-AO) implementation was fixed by restoring the RCU grace period in the tcp_ao_destroy_sock function. The flaw allowed a race condition where a freed pointer could be accessed concurrently by softirq readers, potentially causing memory corruption and kernel crashes. This issue affects multiple Linux kernel versions prior to 7.0.0 and was resolved by re-adding RCU callbacks to ensure safe memory reclamation.
References
- ubuntu.com/security/CVE-2026-64459 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64459 (opens in a new tab)
- git.kernel.org/linus/8bc4d43bccbd60efe85d0a44d5bf41762f2f0c30 (opens in a new tab)
- git.kernel.org/stable/c/4caf12c778fed3dc3824cf36263be5e2c491fbd0 (opens in a new tab)
- git.kernel.org/stable/c/657646c08c94ef7b9dbe468fe7828032216f9841 (opens in a new tab)
- git.kernel.org/stable/c/8bc4d43bccbd60efe85d0a44d5bf41762f2f0c30 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8727-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8800-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-3 (opens in a new tab)