In 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.
Fix
Nothing published yet: no patch, vendor advisory or mitigation reference on NVD, no vendor advisory in the News for this CVE, not in CISA's KEV, no fixed package version. BaselineWatch does not guess at one.
Public exploits 3
- 0xBlackash/CVE-2026-80844 PoC on GitHub
- HORKimhab/CVE-2026-80844 PoC on GitHub
- suominen/dirtyah6 PoC on GitHub
Each line links to the index that lists it, never to exploit code. Exploit-DB's "verified" and a Metasploit rank of good or better count as verified; a PoC-in-GitHub entry is a repository's claim.
Change history 2
- StatusReceived → PublishedNVD modified 2026-10-19 08:44
- First seenunscoredNVD modified 2026-10-19 09:17
Affected (CPE criteria) 0
NVD has not attached CPE configurations yet.
References 9
- https://git.kernel.org/stable/c/0bf11081ad3753938a2b48723ce6298dbac743a1
- https://git.kernel.org/stable/c/1516e31ac458a738be485620579d8f7fb2700fcb
- https://git.kernel.org/stable/c/1b7e066eabcc7d6d8f476c34739b45932f2f4c31
- https://git.kernel.org/stable/c/2dc650956e4e163b879b3fb1027f9557abc5c985
- https://git.kernel.org/stable/c/46640c814f25f096b0b0045ca50e1b7030cd8a30
- https://git.kernel.org/stable/c/48b0e36cf54358276ee7aa897034c973097d2bc9
- https://git.kernel.org/stable/c/6733ae71268a27d598cfb3f3339a3c950b9b656d
- https://git.kernel.org/stable/c/7bad4bda74dc4713f398d3b7624ff05478e3a568
- https://git.kernel.org/stable/c/f00df8500e5a36ba70d336fd34bd2152ea074e5f