CVE-2026-80844
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.
Affected versions
Linux kernel versions
2.6.12
and later are affected. Fixed in
5.10.269,
5.15.220,
6.1.187,
6.6.156,
6.12.108,
6.18.49,
7.1.13,
7.2.3,
7.3
and their respective stable series.
References
9 totalFrequently asked questions
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What is CVE-2026-80844?
CVE-2026-80844 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 2.6.12 onward and has been patched in 5.10.269, 5.15.220, 6.1.187 and others. CVE-2026-80844 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-80844?
Yes. CVE-2026-80844 has been patched. Fixed versions include 5.10.269, 5.15.220, 6.1.187 and others. If you are running Linux kernel 2.6.12 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-80844 actively exploited?
No. CVE-2026-80844 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.