{
  "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-2026-23300",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-23300",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-03-25T10:26:56.138Z",
    "updatedAt": "2026-10-15T01:13:50.190Z",
    "importedAt": "2026-10-24T01:58:02.025Z",
    "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": "net: ipv6: fix panic when IPv4 route references loopback IPv6 nexthop",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ipv6: fix panic when IPv4 route references loopback IPv6 nexthop\n\nWhen a standalone IPv6 nexthop object is created with a loopback device\n(e.g., \"ip -6 nexthop add id 100 dev lo\"), fib6_nh_init() misclassifies\nit as a reject route. This is because nexthop objects have no destination\nprefix (fc_dst=::), causing fib6_is_reject() to match any loopback\nnexthop. The reject path skips fib_nh_common_init(), leaving\nnhc_pcpu_rth_output unallocated. If an IPv4 route later references this\nnexthop, __mkroute_output() dereferences NULL nhc_pcpu_rth_output and\npanics.\n\nSimplify the check in fib6_nh_init() to only match explicit reject\nroutes (RTF_REJECT) instead of using fib6_is_reject(). The loopback\npromotion heuristic in fib6_is_reject() is handled separately by\nip6_route_info_create_nh(). After this change, the three cases behave\nas follows:\n\n1. Explicit reject route (\"ip -6 route add unreachable 2001:db8::/64\"):\n   RTF_REJECT is set, enters reject path, skips fib_nh_common_init().\n   No behavior change.\n\n2. Implicit loopback reject route (\"ip -6 route add 2001:db8::/32 dev lo\"):\n   RTF_REJECT is not set, takes normal path, fib_nh_common_init() is\n   called. ip6_route_info_create_nh() still promotes it to reject\n   afterward. nhc_pcpu_rth_output is allocated but unused, which is\n   harmless.\n\n3. Standalone nexthop object (\"ip -6 nexthop add id 100 dev lo\"):\n   RTF_REJECT is not set, takes normal path, fib_nh_common_init() is\n   called. nhc_pcpu_rth_output is properly allocated, fixing the crash\n   when IPv4 routes reference this nexthop.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "493ced1ac47c48bb86d9d4e8e87df8592be85a0e",
              "status": "affected",
              "versionType": "git",
              "lessThan": "607e68c1b7c5a30c795571be1906d716e989a644"
            },
            {
              "version": "493ced1ac47c48bb86d9d4e8e87df8592be85a0e",
              "status": "affected",
              "versionType": "git",
              "lessThan": "c11d7c56c2076ee9cd72004f1976fe0734df2ae9"
            },
            {
              "version": "493ced1ac47c48bb86d9d4e8e87df8592be85a0e",
              "status": "affected",
              "versionType": "git",
              "lessThan": "b5062fc2150614c9ea8a611c2e0cb6e047ebfa3a"
            },
            {
              "version": "493ced1ac47c48bb86d9d4e8e87df8592be85a0e",
              "status": "affected",
              "versionType": "git",
              "lessThan": "b299121e7453d23faddf464087dff513a495b4fc"
            },
            {
              "version": "493ced1ac47c48bb86d9d4e8e87df8592be85a0e",
              "status": "affected",
              "versionType": "git",
              "lessThan": "f7c9f8e3607440fe39300efbaf46cf7b5eecb23f"
            },
            {
              "version": "493ced1ac47c48bb86d9d4e8e87df8592be85a0e",
              "status": "affected",
              "versionType": "git",
              "lessThan": "b3b5a037d520afe3d5276e653bc0ff516bbda34c"
            },
            {
              "version": "493ced1ac47c48bb86d9d4e8e87df8592be85a0e",
              "status": "affected",
              "versionType": "git",
              "lessThan": "8650db85b4259d2885d2a80fbc2317ce24194133"
            },
            {
              "version": "493ced1ac47c48bb86d9d4e8e87df8592be85a0e",
              "status": "affected",
              "versionType": "git",
              "lessThan": "21ec92774d1536f71bdc90b0e3d052eff99cf093"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "5.3",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "5.3"
            },
            {
              "version": "5.10.253",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "version": "5.15.203",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "version": "6.1.167",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "version": "6.6.130",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "version": "6.12.77",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.18.17",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "version": "6.19.7",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.19.*"
            },
            {
              "version": "7.0",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}