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CVE-2026-98241

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: ipv6: xfrm: use full sockets in local error paths xfrm6_local_rxpmtu() and xfrm6_local_error() dereference skb->sk as if it always pointed at a full IPv6 socket. That is not guaranteed. TCP SYN-ACK skbs can be owned by a TCP_NEW_SYN_RECV request_sock while the output path itself is driven by the full listener. If rerouting selects an IPv6 XFRM tunnel route with a lower MTU, the local PMTU/error handling path can reach these callbacks with that mini-socket still attached to the skb. The callbacks then miscast the request socket as a full inet/IPv6 socket and can read beyond the request_sock allocation when they access inet_sock or ipv6_pinfo state. Resolve the owner with skb_to_full_sk() in both callbacks and bail out when no full socket is attached. This matches the surrounding XFRM IPv6 PMTU/error logic, which already reasons about full sockets with skb_to_full_sk().

Severity
HIGH
CVSS score
7.8 (v3.1)
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-10-06 09:18:12.090000
Last modified
2026-10-19 10:18:24.967000
View original CVE JSON
{
  "id": "CVE-2026-98241",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-06T09:18:12.090",
  "lastModified": "2026-10-19T10:18:24.967",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: xfrm: use full sockets in local error paths\n\nxfrm6_local_rxpmtu() and xfrm6_local_error() dereference skb->sk as if it\nalways pointed at a full IPv6 socket.\n\nThat is not guaranteed. TCP SYN-ACK skbs can be owned by a\nTCP_NEW_SYN_RECV request_sock while the output path itself is driven by the\nfull listener. If rerouting selects an IPv6 XFRM tunnel route with a lower\nMTU, the local PMTU/error handling path can reach these callbacks with that\nmini-socket still attached to the skb.\n\nThe callbacks then miscast the request socket as a full inet/IPv6 socket and\ncan read beyond the request_sock allocation when they access inet_sock or\nipv6_pinfo state.\n\nResolve the owner with skb_to_full_sk() in both callbacks and bail out when\nno full socket is attached. This matches the surrounding XFRM IPv6 PMTU/error\nlogic, which already reasons about full sockets with skb_to_full_sk()."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "net/ipv6/xfrm6_output.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "dd767856a36e00b631d65ebc4bb81b19915532d6",
              "lessThan": "b1a88633c36d2cbc3831382f3846754d344276fd",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "dd767856a36e00b631d65ebc4bb81b19915532d6",
              "lessThan": "904a0e827d0d7189271a3a2eb648293809f25efc",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "dd767856a36e00b631d65ebc4bb81b19915532d6",
              "lessThan": "675919e08ce266b8cac11fd9af29170e762a480f",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "dd767856a36e00b631d65ebc4bb81b19915532d6",
              "lessThan": "60459c670329d586a58db5d8f811fa5accfe4862",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "dd767856a36e00b631d65ebc4bb81b19915532d6",
              "lessThan": "ca3d68c3213475b53db6647e159dc73bd1af5ab1",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "dd767856a36e00b631d65ebc4bb81b19915532d6",
              "lessThan": "4c030a0400ebfd2318361c923a88103b2c67c49f",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "dd767856a36e00b631d65ebc4bb81b19915532d6",
              "lessThan": "c21f3f7fbfeda7c5794f606cb0ffcc2d9001eef8",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "dd767856a36e00b631d65ebc4bb81b19915532d6",
              "lessThan": "6973a21ee73c5567f883813c8ef414774b45892f",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "net/ipv6/xfrm6_output.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "3.2",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "3.2",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.10.271",
              "lessThanOrEqual": "5.10.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.15.222",
              "lessThanOrEqual": "5.15.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.189",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.158",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.112",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.54",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.8",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/4c030a0400ebfd2318361c923a88103b2c67c49f",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/60459c670329d586a58db5d8f811fa5accfe4862",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/675919e08ce266b8cac11fd9af29170e762a480f",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/6973a21ee73c5567f883813c8ef414774b45892f",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/904a0e827d0d7189271a3a2eb648293809f25efc",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b1a88633c36d2cbc3831382f3846754d344276fd",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/c21f3f7fbfeda7c5794f606cb0ffcc2d9001eef8",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/ca3d68c3213475b53db6647e159dc73bd1af5ab1",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}