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CVE-2026-80844

xfrm: ah6: validate routing header segments_left PUBLISHED

Description (CNA)

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 (CNA)

Vendor / productVersions
Linux / Linuxaffected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 2dc650956e4e163b879b3fb1027f9557abc5c985; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 48b0e36cf54358276ee7aa897034c973097d2bc9; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 1b7e066eabcc7d6d8f476c34739b45932f2f4c31; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before f00df8500e5a36ba70d336fd34bd2152ea074e5f; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 1516e31ac458a738be485620579d8f7fb2700fcb; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 6733ae71268a27d598cfb3f3339a3c950b9b656d; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 0bf11081ad3753938a2b48723ce6298dbac743a1; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 46640c814f25f096b0b0045ca50e1b7030cd8a30; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 7bad4bda74dc4713f398d3b7624ff05478e3a568
Linux / Linuxaffected 2.6.12; unaffected 0 before 2.6.12; unaffected 5.10.269 through 5.10.*; unaffected 5.15.220 through 5.15.*; unaffected 6.1.187 through 6.1.*; unaffected 6.6.156 through 6.6.*; unaffected 6.12.108 through 6.12.*; unaffected 6.18.49 through 6.18.*; unaffected 7.1.13 through 7.1.*; unaffected 7.2.3 through 7.2.*; unaffected 7.3 through *

CWE

No CWE identifiers supplied.

References