{
  "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-2026-55996",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-55996",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-08-05T07:46:43.831Z",
    "updatedAt": "2026-08-05T19:05:26.627Z",
    "importedAt": "2026-10-24T01:58:20.586Z",
    "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": "Unauthenticated Denial-of-Service via TLS SAN Stuffing in Rancher and cattle-cluster-agent",
      "summary": "A denial-of-service vulnerability was identified in multiple TLS listeners in Rancher. Both the cattle-cluster-agent component running in downstream clusters and the Rancher server itself use the dynamiclistener library to serve TLS traffic. Without an effective CN filter configured, dynamiclistener automatically appended to each serving certificate any hostname presented via Server Name Indication (SNI) in incoming TLS requests.\n\n\n\nAn unauthenticated attacker with network access within the affected cluster could send a large number of TLS requests with distinct hostnames, causing the serving certificate to accumulate an unbounded number of Subject Alternative Names (SANs). Eventually, the certificate grows large enough that TLS handshakes fail with an excessive message size error, causing a denial of service on the affected listeners.",
      "affected": [
        {
          "vendor": "SUSE",
          "product": "Rancher",
          "packageName": "Rancher",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "2.11.0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "2.11.16"
            },
            {
              "version": "2.12.0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "2.12.12"
            },
            {
              "version": "2.13.0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "2.13.8"
            },
            {
              "version": "2.14.0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "2.14.4"
            }
          ]
        }
      ]
    }
  }
}