{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-21637", "assignerOrgId": "36234546-b8fa-4601-9d6f-f4e334aa8ea1", "state": "PUBLISHED", "assignerShortName": "hackerone", "dateReserved": "2026-01-01T15:00:02.339Z", "datePublished": "2026-01-20T20:41:55.352Z", "dateUpdated": "2026-01-20T20:41:55.352Z"}, "containers": {"cna": {"descriptions": [{"lang": "en", "value": "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": [{"defaultStatus": "unaffected", "vendor": "nodejs", "product": "node", "versions": [{"version": "20.19.6", "status": "affected", "lessThanOrEqual": "20.19.6", "versionType": "semver"}, {"version": "22.21.1", "status": "affected", "lessThanOrEqual": "22.21.1", "versionType": "semver"}, {"version": "24.12.0", "status": "affected", "lessThanOrEqual": "24.12.0", "versionType": "semver"}, {"version": "25.2.1", "status": "affected", "lessThanOrEqual": "25.2.1", "versionType": "semver"}, {"version": "4.0", "status": "affected", "lessThan": "4.*", "versionType": "semver"}, {"version": "5.0", "status": "affected", "lessThan": "5.*", "versionType": "semver"}, {"version": "6.0", "status": "affected", "lessThan": "6.*", "versionType": "semver"}, {"version": "7.0", "status": "affected", "lessThan": "7.*", "versionType": "semver"}, {"version": "8.0", "status": "affected", "lessThan": "8.*", "versionType": "semver"}, {"version": "9.0", "status": "affected", "lessThan": "9.*", "versionType": "semver"}, {"version": "10.0", "status": "affected", "lessThan": "10.*", "versionType": "semver"}, {"version": "11.0", "status": "affected", "lessThan": "11.*", "versionType": "semver"}, {"version": "12.0", "status": "affected", "lessThan": "12.*", "versionType": "semver"}, {"version": "13.0", "status": "affected", "lessThan": "13.*", "versionType": "semver"}, {"version": "14.0", "status": "affected", "lessThan": "14.*", "versionType": "semver"}, {"version": "15.0", "status": "affected", "lessThan": "15.*", "versionType": "semver"}, {"version": "16.0", "status": "affected", "lessThan": "16.*", "versionType": "semver"}, {"version": "17.0", "status": "affected", "lessThan": "17.*", "versionType": "semver"}, {"version": "18.0", "status": "affected", "lessThan": "18.*", "versionType": "semver"}]}], "references": [{"url": "https://nodejs.org/en/blog/vulnerability/december-2025-security-releases"}], "metrics": [{"cvssV3_0": {"version": "3.0", "vectorString": "CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.9, "baseSeverity": "MEDIUM"}}], "providerMetadata": {"orgId": "36234546-b8fa-4601-9d6f-f4e334aa8ea1", "shortName": "hackerone", "dateUpdated": "2026-01-20T20:41:55.352Z"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "id": "CVE-2026-21637", "lastModified": "2026-01-20T21:16:05.950", "metrics": {"cvssMetricV30": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 5.9, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.0"}, "exploitabilityScore": 2.2, "impactScore": 3.6, "source": "support@hackerone.com", "type": "Secondary"}]}, "published": "2026-01-20T21:16:05.950", "references": [{"source": "support@hackerone.com", "url": "https://nodejs.org/en/blog/vulnerability/december-2025-security-releases"}], "sourceIdentifier": "support@hackerone.com", "vulnStatus": "Received"}

{"bugzilla": {"description": "nodejs: Nodejs denial of service", "id": "2431340", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2431340"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.9", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-248", "details": ["No description is available for this CVE."], "mitigation": {"lang": "en:us", "value": "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability."}, "name": "CVE-2026-21637", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "nodejs22", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "nodejs24", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "nodejs:20/nodejs", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "nodejs:22/nodejs", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "nodejs:24/nodejs", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "nodejs:20/nodejs", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "nodejs:22/nodejs", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "nodejs:24/nodejs", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-01-20T20:41:55Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-21637\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-21637\nhttps://nodejs.org/en/blog/vulnerability/december-2025-security-releases"], "threat_severity": "Moderate"}

{"created": "2026-01-21T11:18:54.871031+00:00", "updated": "2026-01-21T11:18:54.871058+00:00", "vendors": ["nodejs", "nodejs$PRODUCT$nodejs"]}