CVE-2026-64525: Linux kernel · xfrm: move policy_bydst RCU sync from per-netns .exit to .pre_exit
Affects Linux kernelSource GCVE Database
Not known to be exploited · fixed in 6.8.0-1066.69~22.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 17:16 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.8.0-1066.69~22.04.1, 6.8.0-1070.78~22.04.1, 6.8.0-1068.75~22.04.1 +36
Exploitation 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.
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
Patches are available and should be applied to affected Linux kernel versions to resolve this issue. The vendor advisory confirms that the flaw has been fixed in updated kernel releases. Users should update to the fixed versions as listed in the advisory.
Description
A medium severity vulnerability in the Linux kernel's xfrm subsystem was fixed by changing the timing of RCU synchronization during network namespace teardown. The original code called synchronize_rcu() in an exit handler, violating kernel guidelines and causing inefficient cleanup and potential issues. This flaw has been addressed in updated Linux kernel versions with patches available.
References
- nvd.nist.gov/vuln/detail/CVE-2026-64525 (opens in a new tab)
- git.kernel.org/stable/c/3e52417318473782012b236d0325bf7d2266a597 (opens in a new tab)
- git.kernel.org/stable/c/91cc13978ab0bc6f669139f53e7e613a860d10e0 (opens in a new tab)
- git.kernel.org/stable/c/bca6386dc08750fc7cdcbc7683473748ba3114b9 (opens in a new tab)
- git.kernel.org/stable/c/d14ae8ef88c2c6590e107db61b6adce148cec7b3 (opens in a new tab)
- ubuntu.com/security/CVE-2026-64525 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64525 (opens in a new tab)
- git.kernel.org/linus/3e52417318473782012b236d0325bf7d2266a597 (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)
- ubuntu.com/security/notices/USN-8728-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8903-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8905-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8906-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8904-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8903-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8905-2 (opens in a new tab)