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CVE-2026-98952

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: pfcp: make sure the SEID is linear before reading it pfcp_encap_recv() only makes sure that the UDP header and the 4 byte PFCP header are in the linear area. When the S flag is set, pfcp_session_recv() then reads the 8 byte SEID that follows, which is not covered by the pskb_may_pull() check. A short PFCP packet with the S flag set, or one whose session header lies in a fragment, therefore makes pfcp_session_recv() read beyond the end of the packet data, and whatever it finds there is stored in the tunnel metadata that flower later classifies on. Pull up to the end of the SEID before reading it, and drop packets that are too short to contain it. Reload the header pointer afterwards since pskb_may_pull() may reallocate the skb head. Use offsetofend() rather than sizeof(struct pfcphdr_session): the structure is not packed, so its size is 16 bytes because of the alignment of the __be64 member, while the header on the wire is only 12 bytes, and valid session messages would be dropped.

Severity
HIGH
CVSS score
7.3 (v3.1)
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-10-23 13:17:16.370000
Last modified
2026-10-24 14:16:49.163000
View original CVE JSON
{
  "id": "CVE-2026-98952",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-23T13:17:16.370",
  "lastModified": "2026-10-24T14:16:49.163",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\npfcp: make sure the SEID is linear before reading it\n\npfcp_encap_recv() only makes sure that the UDP header and the 4 byte\nPFCP header are in the linear area. When the S flag is set,\npfcp_session_recv() then reads the 8 byte SEID that follows, which is\nnot covered by the pskb_may_pull() check.\n\nA short PFCP packet with the S flag set, or one whose session header\nlies in a fragment, therefore makes pfcp_session_recv() read beyond the\nend of the packet data, and whatever it finds there is stored in the\ntunnel metadata that flower later classifies on.\n\nPull up to the end of the SEID before reading it, and drop packets\nthat are too short to contain it. Reload the header pointer afterwards\nsince pskb_may_pull() may reallocate the skb head.\n\nUse offsetofend() rather than sizeof(struct pfcphdr_session): the\nstructure is not packed, so its size is 16 bytes because of the\nalignment of the __be64 member, while the header on the wire is only 12\nbytes, and valid session messages would be dropped."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/net/pfcp.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6dd514f48110ebb4bf36875b9e7e02d07b589caa",
              "lessThan": "3192a5e398c64d48aad64a09e29643e327369bc4",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "6dd514f48110ebb4bf36875b9e7e02d07b589caa",
              "lessThan": "b18a6496495495e2dc27e525aa3315a0c59b9513",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "6dd514f48110ebb4bf36875b9e7e02d07b589caa",
              "lessThan": "2fb6d05f706d79bbdc88835be2f4f45ab56dd819",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "6dd514f48110ebb4bf36875b9e7e02d07b589caa",
              "lessThan": "23609bce9e1de525d1d0e73fc68c6e7971d0b49e",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/net/pfcp.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.10",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.10",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.113",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.57",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.11",
              "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:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
          "baseScore": 7.3,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "availabilityImpact": "LOW"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.4
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/23609bce9e1de525d1d0e73fc68c6e7971d0b49e",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/2fb6d05f706d79bbdc88835be2f4f45ab56dd819",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/3192a5e398c64d48aad64a09e29643e327369bc4",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b18a6496495495e2dc27e525aa3315a0c59b9513",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}