GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

CVE-2026-80844 (GCVE-0-2026-80844)

Vulnerability from cvelistv5 – Published: 2026-09-04 15:54 – Updated: 2026-09-04 15:54
VLAI
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
Impacted 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 Create a notification for this product.
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 Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "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": [
            {
              "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"
            }
          ]
        }
      ],
      "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:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.108",
                  "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": "2026-09-14",
      "epss": "0.00195",
      "percentile": "0.09373"
    },
    "microsoft_vex": {
      "current_release_date": "2026-09-07T02:03:28.000Z",
      "cve": "CVE-2026-80844",
      "id": "msrc_CVE-2026-80844",
      "initial_release_date": "2026-09-06T04:36:08.000Z",
      "product_status:known_affected": "1",
      "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": "2"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-80844\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-09-04T16:18:13.023\",\"lastModified\":\"2026-09-04T16:18:13.023\",\"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\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.\"}],\"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\":[{\"version\":\"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\",\"lessThan\":\"2dc650956e4e163b879b3fb1027f9557abc5c985\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\",\"lessThan\":\"48b0e36cf54358276ee7aa897034c973097d2bc9\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\",\"lessThan\":\"1b7e066eabcc7d6d8f476c34739b45932f2f4c31\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\",\"lessThan\":\"f00df8500e5a36ba70d336fd34bd2152ea074e5f\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\",\"lessThan\":\"1516e31ac458a738be485620579d8f7fb2700fcb\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\",\"lessThan\":\"6733ae71268a27d598cfb3f3339a3c950b9b656d\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\",\"lessThan\":\"0bf11081ad3753938a2b48723ce6298dbac743a1\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\",\"lessThan\":\"46640c814f25f096b0b0045ca50e1b7030cd8a30\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2\",\"lessThan\":\"7bad4bda74dc4713f398d3b7624ff05478e3a568\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"net/ipv6/ah6.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"2.6.12\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"2.6.12\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.10.269\",\"lessThanOrEqual\":\"5.10.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.220\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.187\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.156\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.108\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.49\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.13\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2.3\",\"lessThanOrEqual\":\"7.2.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.3-rc1\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"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\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-09-08T17:16:20Z",
      "cve": "CVE-2026-80844",
      "id": "CVE-2026-80844",
      "initial_release_date": "2026-09-05T00:26:22Z",
      "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": "3"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





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.


Detection rules are retrieved from Rulezet.