{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "4cb47a8644cc9eb8ec81190a50e79e6530d0297f"
            },
            {
              "fixed": "5a92cb45e34749865d03daf8d3500f77b5f6644c"
            },
            {
              "fixed": "c7b7ec3e69e673c0d6b57f74d21da50c485c598e"
            },
            {
              "fixed": "7f4f7efe7f30edd29c4988de01728bf2398217e4"
            },
            {
              "fixed": "e917d0c69f01af2bb4fbea2b66d560a53b3ac7ec"
            },
            {
              "fixed": "a096b6e34f602950af9a2b0856cd93a5f4c276d7"
            },
            {
              "fixed": "43368636c663cff6e59dde93cf4b8e43ac28eb93"
            },
            {
              "fixed": "cb549df9ce4ee15c9d5b19ddab12cf2128e4313c"
            },
            {
              "fixed": "509323077ef79a26ba0c60bb556e45c12c398b2d"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.9.0"
            },
            {
              "fixed": "5.10.259"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.210"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.176"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.143"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.93"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.35"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.0.12"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63992.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ntunnels: do not assume transport header in iptunnel_pmtud_check_icmp()\n\nIn some cases, iptunnel_pmtud_check_icmp() can be called while\nskb transport header is not set.\n\nThis triggers an out-of-bound access, because\n(typeof(skb-\u003etransport_header))~0U is 65535.\n\nAccess the icmp header based on IPv4 network header,\nafter making sure icmp-\u003etype is present in skb linear part.\n\nNote that iptunnel_pmtud_check_icmpv6()) is fine.",
  "id": "CVE-2026-63992",
  "modified": "2026-07-22T05:29:59.708125709Z",
  "published": "2026-07-19T14:56:12.528Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/43368636c663cff6e59dde93cf4b8e43ac28eb93"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/509323077ef79a26ba0c60bb556e45c12c398b2d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5a92cb45e34749865d03daf8d3500f77b5f6644c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7f4f7efe7f30edd29c4988de01728bf2398217e4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a096b6e34f602950af9a2b0856cd93a5f4c276d7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c7b7ec3e69e673c0d6b57f74d21da50c485c598e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cb549df9ce4ee15c9d5b19ddab12cf2128e4313c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e917d0c69f01af2bb4fbea2b66d560a53b3ac7ec"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63992.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63992"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "tunnels: do not assume transport header in iptunnel_pmtud_check_icmp()"
}