CVE-2026-80844
N/AIn the Linux kernel, the following vulnerability has been resolved: xfrm: ah6: validate routing header segments_left AH6 rearranges routing-header addresses before computing or verifying the ICV. ipv6_rearrange_rthdr() assumes that segments_left is not larger than the number of addresses described by the routing header's hdrlen field. That assumption does not hold for raw IPv6 HDRINCL packets. A packet with hdrlen equal to 2 describes one address, but can carry an arbitrary segments_left value. With segments_left equal to 255, the function moves its address pointer 4,064 bytes backwards and passes a 4,064-byte length to memmove(), resulting in an out-of-bounds access. Validate the invariant locally before modifying the routing header or performing any address-pointer arithmetic, and propagate malformed-header errors to the existing AH6 input and output error paths.
No known exploitation, public exploit, or elevated probability at this time. Track for changes.
Exploitation likelihood
—EPSS not yet scored
Impact if exploited
—CVSS · not scored
- No impact metrics
Proof of concept & exploit code
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-80844/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-80844/poc.json
References
Technical & other
- https://git.kernel.org/stable/c/2dc650956e4e163b879b3fb1027f9557abc5c985
- https://git.kernel.org/stable/c/48b0e36cf54358276ee7aa897034c973097d2bc9
- https://git.kernel.org/stable/c/1b7e066eabcc7d6d8f476c34739b45932f2f4c31
- https://git.kernel.org/stable/c/f00df8500e5a36ba70d336fd34bd2152ea074e5f
- https://git.kernel.org/stable/c/1516e31ac458a738be485620579d8f7fb2700fcb
- https://git.kernel.org/stable/c/6733ae71268a27d598cfb3f3339a3c950b9b656d
- https://git.kernel.org/stable/c/0bf11081ad3753938a2b48723ce6298dbac743a1
- https://git.kernel.org/stable/c/46640c814f25f096b0b0045ca50e1b7030cd8a30
- https://git.kernel.org/stable/c/7bad4bda74dc4713f398d3b7624ff05478e3a568