CVE-2026-64566: Linux kernel · xfrm: iptfs: propagate SKBFL_SHARED_FRAG in iptfs_skb_add_frags()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical.
Data as of 3 Nov 2026, 18:30 UTC
Thin evidence
One scorer or none| CNA (Linux) | CVSS 3.1 | 9.8 |
|---|
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 5 Aug 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 3 Nov 2026.
What to do
AI-suggested
A fix for this vulnerability has been released by the Linux kernel maintainers. Users should apply the official kernel updates that include the corrected iptfs_skb_add_frags() function which properly propagates the SKBFL_SHARED_FRAG flag. No additional mitigations are specified beyond applying the patch.
Description
CVE-2026-64566 is a critical vulnerability in the Linux kernel's xfrm subsystem related to the iptfs_skb_add_frags() function. The flaw involves improper propagation of the SKBFL_SHARED_FRAG flag when copying fragment references, leading to kernel memory corruption and potential system panic during ESP packet processing in nested transport-mode SAs.