cipso: adjust cached option offsets when removing CIPSO

{
  "id": "5cd09f4a2605497950f176389e987c9075841b51f168fb78efc04d7dadb2008d",
  "url": "https://osv.dev/vulnerability/CVE-2026-99064",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "cipso: adjust cached option offsets when removing CIPSO",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: cipso: adjust cached option offsets when removing CIPSO cipso_v4_skbuff_delattr() removes the CIPSO bytes but does not adjust cached offsets for options that follow them. For example, with a valid 10-byte CIPSO option followed by a seven-byte RR option, parsing records rr at offset 30. Removing CIPSO moves RR to offset 20, while the cached offset remains 30. Consumers such as ip_forward_options() and __ip_options_echo() then access the wrong bytes; the latter may interpret packet data as the option length and copy it into fixed-size option storage. Mirror cipso_v4_delopt() and subtract cipso_len from the srr, rr, ts and router_alert offsets when they follow CIPSO. cipso_len is the distance the first memmove() shifts those options. The later header move and network-header reset relocate the bytes and their offset base together.",
    "evidence": "osv:CVE-2026-99064",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.12.113",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.57",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.2.11",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-99064",
      "aliases": [
        "CVE-2026-99064"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "89aa3619d141d6cfb6040a561aebb6d99d3e2285"
                },
                {
                  "fixed": "b965977126a90e01825814c859ba4788691eddd3"
                },
                {
                  "fixed": "2200fe1d6148b78e1b8f00f4b2bd47760015077f"
                },
                {
                  "fixed": "6e49d611a9cfbaac927b8fa80ebd4f6b1f37ada0"
                },
                {
                  "fixed": "6d25ffca055a77787c21a36b66c253f76239411b"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-99064.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.10.0"
                },
                {
                  "fixed": "6.12.113"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.18.57"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.2.11"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-99064.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:50.257661972Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/2200fe1d6148b78e1b8f00f4b2bd47760015077f",
        "https://git.kernel.org/stable/c/6d25ffca055a77787c21a36b66c253f76239411b",
        "https://git.kernel.org/stable/c/6e49d611a9cfbaac927b8fa80ebd4f6b1f37ada0",
        "https://git.kernel.org/stable/c/b965977126a90e01825814c859ba4788691eddd3",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/99xxx/CVE-2026-99064.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-99064",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/99xxx/CVE-2026-99064.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-99064",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 518962,
  "published_at": "2026-10-23T12:23:05.854+00:00"
}