{
  "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-2026-21637",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-21637",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-01-20T20:41:55.352Z",
    "updatedAt": "2026-01-21T20:22:51.033Z",
    "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": null,
      "summary": "A flaw in Node.js TLS error handling allows remote attackers to crash or exhaust resources of a TLS server when `pskCallback` or `ALPNCallback` are in use. Synchronous exceptions thrown during these callbacks bypass standard TLS error handling paths (tlsClientError and error), causing either immediate process termination or silent file descriptor leaks that eventually lead to denial of service. Because these callbacks process attacker-controlled input during the TLS handshake, a remote client can repeatedly trigger the issue. This vulnerability affects TLS servers using PSK or ALPN callbacks across Node.js versions where these callbacks throw without being safely wrapped.",
      "affected": [
        {
          "vendor": "nodejs",
          "product": "node",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "20.19.6",
              "status": "affected",
              "versionType": "semver",
              "lessThanOrEqual": "20.19.6"
            },
            {
              "version": "22.21.1",
              "status": "affected",
              "versionType": "semver",
              "lessThanOrEqual": "22.21.1"
            },
            {
              "version": "24.12.0",
              "status": "affected",
              "versionType": "semver",
              "lessThanOrEqual": "24.12.0"
            },
            {
              "version": "25.2.1",
              "status": "affected",
              "versionType": "semver",
              "lessThanOrEqual": "25.2.1"
            },
            {
              "version": "4.0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "4.*"
            },
            {
              "version": "5.0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "5.*"
            },
            {
              "version": "6.0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.*"
            },
            {
              "version": "7.0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "7.*"
            },
            {
              "version": "8.0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "8.*"
            },
            {
              "version": "9.0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "9.*"
            },
            {
              "version": "10.0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "10.*"
            },
            {
              "version": "11.0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "11.*"
            },
            {
              "version": "12.0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "12.*"
            },
            {
              "version": "13.0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "13.*"
            },
            {
              "version": "14.0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "14.*"
            },
            {
              "version": "15.0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "15.*"
            },
            {
              "version": "16.0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "16.*"
            },
            {
              "version": "17.0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "17.*"
            },
            {
              "version": "18.0",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "18.*"
            }
          ]
        }
      ]
    }
  }
}