CVE-2026-80844 (GCVE-0-2026-80844)
Vulnerability from cvelistv5 – Published: 2026-09-04 15:54 – Updated: 2026-09-04 15:54
VLAI
EPSS
VEX
Title
xfrm: ah6: validate routing header segments_left
Summary
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
No CVSS data available.
Assigner
References
9 references
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 2dc650956e4e163b879b3fb1027f9557abc5c985
(git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 48b0e36cf54358276ee7aa897034c973097d2bc9 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 1b7e066eabcc7d6d8f476c34739b45932f2f4c31 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < f00df8500e5a36ba70d336fd34bd2152ea074e5f (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 1516e31ac458a738be485620579d8f7fb2700fcb (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 6733ae71268a27d598cfb3f3339a3c950b9b656d (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 0bf11081ad3753938a2b48723ce6298dbac743a1 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 46640c814f25f096b0b0045ca50e1b7030cd8a30 (git) Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 7bad4bda74dc4713f398d3b7624ff05478e3a568 (git) |
guessed | |
| Linux | Linux |
Affected:
2.6.12
Unaffected: 0 , < 2.6.12 (semver) Unaffected: 5.10.269 , ≤ 5.10.* (semver) Unaffected: 5.15.220 , ≤ 5.15.* (semver) Unaffected: 6.1.187 , ≤ 6.1.* (semver) Unaffected: 6.6.156 , ≤ 6.6.* (semver) Unaffected: 6.12.108 , ≤ 6.12.* (semver) Unaffected: 6.18.49 , ≤ 6.18.* (semver) Unaffected: 7.1.13 , ≤ 7.1.* (semver) Unaffected: 7.2.3 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix) |
guessed |
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/ipv6/ah6.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
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"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"versionType": "git"
},
{
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"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
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"versionType": "git"
},
{
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"versionType": "git"
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{
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"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"versionType": "git"
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"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"versionType": "git"
},
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"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"versionType": "git"
},
{
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"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
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{
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"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/ipv6/ah6.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.12"
},
{
"lessThan": "2.6.12",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.269",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.220",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.187",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.156",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.108",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.49",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.13",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.3",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3-rc1",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.10.269",
"versionStartIncluding": "2.6.12",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.15.220",
"versionStartIncluding": "2.6.12",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.1.187",
"versionStartIncluding": "2.6.12",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.156",
"versionStartIncluding": "2.6.12",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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"versionStartIncluding": "2.6.12",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.49",
"versionStartIncluding": "2.6.12",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.13",
"versionStartIncluding": "2.6.12",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2.3",
"versionStartIncluding": "2.6.12",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.3-rc1",
"versionStartIncluding": "2.6.12",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"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\u0027s 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."
}
],
"providerMetadata": {
"dateUpdated": "2026-09-04T15:54:54.295Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"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"
}
],
"title": "xfrm: ah6: validate routing header segments_left",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-80844",
"datePublished": "2026-09-04T15:54:54.295Z",
"dateReserved": "2026-08-26T14:34:25.796Z",
"dateUpdated": "2026-09-04T15:54:54.295Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-80844",
"date": "2026-10-05",
"epss": "0.00434",
"percentile": "0.3544"
},
"microsoft_vex": {
"current_release_date": "2026-09-23T03:00:07.000Z",
"cve": "CVE-2026-80844",
"id": "msrc_CVE-2026-80844",
"initial_release_date": "2026-09-06T04:36:08.000Z",
"product_status:known_affected": "2",
"source": "Microsoft CSAF VEX",
"status": "final",
"title": "xfrm: ah6: validate routing header segments_left",
"url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-80844.json",
"version": "3"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/ipv6/ah6.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "2dc650956e4e163b879b3fb1027f9557abc5c985",
"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"versionType": "git"
},
{
"lessThan": "48b0e36cf54358276ee7aa897034c973097d2bc9",
"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"versionType": "git"
},
{
"lessThan": "1b7e066eabcc7d6d8f476c34739b45932f2f4c31",
"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"versionType": "git"
},
{
"lessThan": "f00df8500e5a36ba70d336fd34bd2152ea074e5f",
"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"versionType": "git"
},
{
"lessThan": "1516e31ac458a738be485620579d8f7fb2700fcb",
"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"versionType": "git"
},
{
"lessThan": "6733ae71268a27d598cfb3f3339a3c950b9b656d",
"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"versionType": "git"
},
{
"lessThan": "0bf11081ad3753938a2b48723ce6298dbac743a1",
"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"versionType": "git"
},
{
"lessThan": "46640c814f25f096b0b0045ca50e1b7030cd8a30",
"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"versionType": "git"
},
{
"lessThan": "7bad4bda74dc4713f398d3b7624ff05478e3a568",
"status": "affected",
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/ipv6/ah6.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.12"
},
{
"lessThan": "2.6.12",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.269",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.220",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.187",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.156",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.108",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.49",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.13",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.3",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3-rc1",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"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\u0027s 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."
}
],
"id": "CVE-2026-80844",
"lastModified": "2026-09-04T16:18:13.023",
"metrics": {},
"published": "2026-09-04T16:18:13.023",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/0bf11081ad3753938a2b48723ce6298dbac743a1"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/1516e31ac458a738be485620579d8f7fb2700fcb"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/1b7e066eabcc7d6d8f476c34739b45932f2f4c31"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/2dc650956e4e163b879b3fb1027f9557abc5c985"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/46640c814f25f096b0b0045ca50e1b7030cd8a30"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/48b0e36cf54358276ee7aa897034c973097d2bc9"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/6733ae71268a27d598cfb3f3339a3c950b9b656d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/7bad4bda74dc4713f398d3b7624ff05478e3a568"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/f00df8500e5a36ba70d336fd34bd2152ea074e5f"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
},
"redhat_vex": {
"aggregate_severity": "Important",
"current_release_date": "2026-10-02T16:50:44+00:00",
"cve": "CVE-2026-80844",
"id": "CVE-2026-80844",
"initial_release_date": "2026-09-04T00:00:00+00:00",
"product_status:fixed": "2336",
"product_status:known_affected": "24",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "kernel: xfrm: ah6: validate routing header segments_left",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80844.json",
"version": "3"
},
"suse_vex": {
"aggregate_severity": "important",
"current_release_date": "2026-10-02T16:48:41Z",
"cve": "CVE-2026-80844",
"id": "CVE-2026-80844",
"initial_release_date": "2026-09-05T00:26:22Z",
"product_status:known_affected": "353",
"product_status:recommended": "78",
"source": "SUSE CSAF VEX",
"status": "interim",
"title": "SUSE CVE CVE-2026-80844",
"url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-80844.json",
"version": "6"
}
}
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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