CVE-2026-80844
Full vulnerability record from the local CVENow database.
Description
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.
Severity
Not scored
CVSS score
Not available
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-09-04 16:18:13.023000
Last modified
2026-10-19 09:17:19.853000
View original CVE JSON
{
"id": "CVE-2026-80844",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-09-04T16:18:13.023",
"lastModified": "2026-10-19T09:17:19.853",
"vulnStatus": "Received",
"cveTags": [],
"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": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"net/ipv6/ah6.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
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"versionType": "git",
"status": "affected"
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"programFiles": [
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],
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"versions": [
{
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{
"version": "0",
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"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.10.269",
"lessThanOrEqual": "5.10.*",
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"status": "unaffected"
},
{
"version": "5.15.220",
"lessThanOrEqual": "5.15.*",
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},
{
"version": "6.1.187",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.156",
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"versionType": "semver",
"status": "unaffected"
},
{
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"versionType": "semver",
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},
{
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},
{
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},
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"versionType": "original_commit_for_fix",
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}
]
}
]
}
],
"metrics": {},
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}