{
  "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-2026-43037",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-43037",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-05-01T14:15:35.314Z",
    "updatedAt": "2026-10-19T19:06:10.690Z",
    "importedAt": "2026-10-24T01:58:08.712Z",
    "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": "ip6_tunnel: clear skb2->cb[] in ip4ip6_err()",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nip6_tunnel: clear skb2->cb[] in ip4ip6_err()\n\nOskar Kjos reported the following problem.\n\nip4ip6_err() calls icmp_send() on a cloned skb whose cb[] was written\nby the IPv6 receive path as struct inet6_skb_parm. icmp_send() passes\nIPCB(skb2) to __ip_options_echo(), which interprets that cb[] region\nas struct inet_skb_parm (IPv4). The layouts differ: inet6_skb_parm.nhoff\nat offset 14 overlaps inet_skb_parm.opt.rr, producing a non-zero rr\nvalue. __ip_options_echo() then reads optlen from attacker-controlled\npacket data at sptr[rr+1] and copies that many bytes into dopt->__data,\na fixed 40-byte stack buffer (IP_OPTIONS_DATA_FIXED_SIZE).\n\nTo fix this we clear skb2->cb[], as suggested by Oskar Kjos.\n\nAlso add minimal IPv4 header validation (version == 4, ihl >= 5).",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "c4d3efafcc933fd2ffd169d7dc4f980393a13796",
              "status": "affected",
              "versionType": "git",
              "lessThan": "ea9f65b27c8404e164848ebff1443310fd187629"
            },
            {
              "version": "c4d3efafcc933fd2ffd169d7dc4f980393a13796",
              "status": "affected",
              "versionType": "git",
              "lessThan": "d6621f60192fe10c047a4487be42a6f4c150707f"
            },
            {
              "version": "c4d3efafcc933fd2ffd169d7dc4f980393a13796",
              "status": "affected",
              "versionType": "git",
              "lessThan": "2cc6e3b0fe0f0242d1f530a93a4924f48ab85ba5"
            },
            {
              "version": "c4d3efafcc933fd2ffd169d7dc4f980393a13796",
              "status": "affected",
              "versionType": "git",
              "lessThan": "a0c4ce9900a108eaf55d0f3b399cb55999647d39"
            },
            {
              "version": "c4d3efafcc933fd2ffd169d7dc4f980393a13796",
              "status": "affected",
              "versionType": "git",
              "lessThan": "1063515ce15ff31065c4e7f8265f4c2fd3c54876"
            },
            {
              "version": "c4d3efafcc933fd2ffd169d7dc4f980393a13796",
              "status": "affected",
              "versionType": "git",
              "lessThan": "590f622669b97eaf7b57a1de7b0a6e68c5d8b2c3"
            },
            {
              "version": "c4d3efafcc933fd2ffd169d7dc4f980393a13796",
              "status": "affected",
              "versionType": "git",
              "lessThan": "4a622658f384b03560834cbe8ffcfe69a278f7c8"
            },
            {
              "version": "c4d3efafcc933fd2ffd169d7dc4f980393a13796",
              "status": "affected",
              "versionType": "git",
              "lessThan": "2edfa31769a4add828a7e604b21cb82aaaa05925"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "2.6.22",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "2.6.22"
            },
            {
              "version": "5.10.253",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "version": "5.15.203",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "version": "6.1.168",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "version": "6.6.134",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "version": "6.12.81",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.18.22",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "version": "6.19.12",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.19.*"
            },
            {
              "version": "7.0",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}