{"id":"CVE-2026-80844","state":"PUBLISHED","title":"xfrm: ah6: validate routing header segments_left","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: ah6: validate routing header segments_left\n\nAH6 rearranges routing-header addresses before computing or verifying the\nICV. ipv6_rearrange_rthdr() assumes that segments_left is not larger than\nthe number of addresses described by the routing header's hdrlen field.\n\nThat assumption does not hold for raw IPv6 HDRINCL packets. A packet with\nhdrlen equal to 2 describes one address, but can carry an arbitrary\nsegments_left value. With segments_left equal to 255, the function moves\nits address pointer 4,064 bytes backwards and passes a 4,064-byte length to\nmemmove(), resulting in an out-of-bounds access.\n\nValidate the invariant locally before modifying the routing header or\nperforming any address-pointer arithmetic, and propagate malformed-header\nerrors to the existing AH6 input and output error paths.","publishedAt":"2026-09-04T15:54:54.295Z","updatedAt":"2026-10-19T08:44:37.342Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"2dc650956e4e163b879b3fb1027f9557abc5c985","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"48b0e36cf54358276ee7aa897034c973097d2bc9","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"1b7e066eabcc7d6d8f476c34739b45932f2f4c31","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"f00df8500e5a36ba70d336fd34bd2152ea074e5f","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"1516e31ac458a738be485620579d8f7fb2700fcb","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"6733ae71268a27d598cfb3f3339a3c950b9b656d","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"0bf11081ad3753938a2b48723ce6298dbac743a1","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"46640c814f25f096b0b0045ca50e1b7030cd8a30","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"7bad4bda74dc4713f398d3b7624ff05478e3a568","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/ah6.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.12","versionType":"semver"},{"version":"5.10.269","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.220","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.187","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.156","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.108","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.49","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.13","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2.3","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/ah6.c"]}],"references":["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"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:07.220Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/80xxx/CVE-2026-80844.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-80844","state":"PUBLISHED","datePublished":"2026-09-04T15:54:54.295Z","dateUpdated":"2026-10-19T08:44:37.342Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-26T14:34:25.796Z"},"containers":{"cna":{"title":"xfrm: ah6: validate routing header segments_left","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: ah6: validate routing header segments_left\n\nAH6 rearranges routing-header addresses before computing or verifying the\nICV. ipv6_rearrange_rthdr() assumes that segments_left is not larger than\nthe number of addresses described by the routing header's hdrlen field.\n\nThat assumption does not hold for raw IPv6 HDRINCL packets. A packet with\nhdrlen equal to 2 describes one address, but can carry an arbitrary\nsegments_left value. With segments_left equal to 255, the function moves\nits address pointer 4,064 bytes backwards and passes a 4,064-byte length to\nmemmove(), resulting in an out-of-bounds access.\n\nValidate the invariant locally before modifying the routing header or\nperforming any address-pointer arithmetic, and propagate malformed-header\nerrors to the existing AH6 input and output error paths."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"2dc650956e4e163b879b3fb1027f9557abc5c985","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"48b0e36cf54358276ee7aa897034c973097d2bc9","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"1b7e066eabcc7d6d8f476c34739b45932f2f4c31","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"f00df8500e5a36ba70d336fd34bd2152ea074e5f","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"1516e31ac458a738be485620579d8f7fb2700fcb","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"6733ae71268a27d598cfb3f3339a3c950b9b656d","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"0bf11081ad3753938a2b48723ce6298dbac743a1","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"46640c814f25f096b0b0045ca50e1b7030cd8a30","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"7bad4bda74dc4713f398d3b7624ff05478e3a568","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/ah6.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.12","versionType":"semver"},{"version":"5.10.269","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.220","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.187","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.156","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.108","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.49","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.13","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2.3","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/ah6.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/2dc650956e4e163b879b3fb1027f9557abc5c985"},{"url":"https://git.kernel.org/stable/c/48b0e36cf54358276ee7aa897034c973097d2bc9"},{"url":"https://git.kernel.org/stable/c/1b7e066eabcc7d6d8f476c34739b45932f2f4c31"},{"url":"https://git.kernel.org/stable/c/f00df8500e5a36ba70d336fd34bd2152ea074e5f"},{"url":"https://git.kernel.org/stable/c/1516e31ac458a738be485620579d8f7fb2700fcb"},{"url":"https://git.kernel.org/stable/c/6733ae71268a27d598cfb3f3339a3c950b9b656d"},{"url":"https://git.kernel.org/stable/c/0bf11081ad3753938a2b48723ce6298dbac743a1"},{"url":"https://git.kernel.org/stable/c/46640c814f25f096b0b0045ca50e1b7030cd8a30"},{"url":"https://git.kernel.org/stable/c/7bad4bda74dc4713f398d3b7624ff05478e3a568"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T08:44:37.342Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.10.269"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.15.220"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.1.187"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.6.156"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.12.108"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.18.49"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"7.1.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"7.2.3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}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