{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2026-99074",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-99074",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-10-23T12:23:17.866Z",
    "updatedAt": "2026-10-23T12:23:17.866Z",
    "importedAt": "2026-10-24T01:58:41.756Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "ipv4: stop PMTU walk when nexthop group shrinks",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv4: stop PMTU walk when nexthop group shrinks\n\nCommit 7d3f3b4367f3 (\"net: ipv4: Cache pmtu for all packet paths if\nmultipath enabled\") made __ip_rt_update_pmtu() update every path.\n\nFor nexthop objects, fib_info_num_path() and fib_info_nhc()\nindependently load nh->nh_grp.  RCU protects each group's lifetime but\ndoes not make the loads observe the same group.  If replacement shrinks\nthe group after the loop accepts an index, fib_info_nhc() returns NULL\nand update_or_create_fnhe() dereferences it.\n\nA deterministic probe only widened the existing window between the real\noperations.  On v7.2, an RTM_NEWNEXTHOP replacement published a\none-member group after the PMTU reader accepted index 1 from a two-member\ngroup, producing:\n\n  KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]\n  RIP: update_or_create_fnhe+0x45/0x15b0\n\nStop when the indexed path is absent.  Groups are dense, so no later\nindex exists in that snapshot.  The same real-writer window completed\n114,423 PMTU iterations without an oops with this check.  A reproducer\nis available on request.\n\nReplacement requires CAP_NET_ADMIN in the network namespace.  Where\nunprivileged user namespaces are permitted, a local user can obtain it\nin a new user and network namespace.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "3bed2abab4a682d426624ce9add9d7b6d475d4e4",
              "status": "affected",
              "versionType": "git",
              "lessThan": "7fd60d3c9a1e1b11ef5f1643bbae78d91eae2f4a"
            },
            {
              "version": "7f5005457b3072fe1ddf15bfef869f2a1d98e05e",
              "status": "affected",
              "versionType": "git",
              "lessThan": "c60d17d6dd61adc761ac6f65a008fefbc54cbf87"
            },
            {
              "version": "7d3f3b4367f315a61fc615e3138f3d320da8c466",
              "status": "affected",
              "versionType": "git",
              "lessThan": "c6d670ac656badfd0e15355e07a13a6bdf3b69fd"
            },
            {
              "version": "7d3f3b4367f315a61fc615e3138f3d320da8c466",
              "status": "affected",
              "versionType": "git",
              "lessThan": "f27483f9975b5065ff67054cc7eb8edac6083488"
            },
            {
              "version": "7d3f3b4367f315a61fc615e3138f3d320da8c466",
              "status": "affected",
              "versionType": "git",
              "lessThan": "6619e01855e65ef35723685a557e3eb106f4ecf5"
            },
            {
              "version": "fc07a232326a623d0be482e307c08ea7049c2846",
              "status": "affected",
              "versionType": "git"
            },
            {
              "version": "b1f7bdee5750d6cbb9497140cd6582abc5fdcb9e",
              "status": "affected",
              "versionType": "git"
            },
            {
              "version": "6.6.79",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.6.160"
            },
            {
              "version": "6.12.16",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.12.113"
            },
            {
              "version": "5.15.179",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "5.16"
            },
            {
              "version": "6.1.129",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.2"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "6.13",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "6.13"
            },
            {
              "version": "6.6.160",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "version": "6.12.113",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.18.57",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "version": "7.2.11",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "7.2.*"
            },
            {
              "version": "7.3",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}