{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-123863", "assignerOrgId": "ce714d77-add3-4f53-aff5-83d477b104bb", "state": "PUBLISHED", "assignerShortName": "openjs", "dateReserved": "2026-11-06T16:12:44.473Z", "datePublished": "2026-11-11T18:16:12.733Z", "dateUpdated": "2026-11-11T18:16:12.733Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "ce714d77-add3-4f53-aff5-83d477b104bb", "shortName": "openjs", "dateUpdated": "2026-11-11T18:16:12.733Z"}, "title": "Node.js is vulnerable to a remote HTTP/2 denial of service via a reachable assertion in Http2Session teardown", "descriptions": [{"lang": "en", "value": "A reachable assertion in Node.js HTTP/2 session teardown lets any unauthenticated client abort the server, over both TLS and cleartext. A client can arrange for an Http2Stream that still holds nghttp2-allocated header buffers to outlive its session: the stream is removed from the session's stream set but never detached, so when ~Http2Session() runs the memory accounting is nonzero and the CHECK_EQ(current_nghttp2_memory_, 0) assertion fails, terminating the process. The trigger needs only a default http2 server whose handler responds before the request body has ended, which is typical. It is a variant of CVE-2024-27983 that the earlier fix did not cover, because that fix only detached streams still tracked in the session. This vulnerability affects Node.js 26.x (since 26.9.0) and 24.x (since 24.22.0).", "supportingMedia": [{"type": "text/markdown", "base64": false, "value": "A reachable assertion in Node.js HTTP/2 session teardown lets any unauthenticated client abort the server, over both TLS and cleartext. A client can arrange for an `Http2Stream` that still holds `nghttp2`-allocated header buffers to outlive its session: the stream is removed from the session's stream set but never detached, so when `~Http2Session()` runs the memory accounting is nonzero and the `CHECK_EQ(current_nghttp2_memory_, 0)` assertion fails, terminating the process. The trigger needs only a default `http2` server whose handler responds before the request body has ended, which is typical. It is a variant of CVE-2024-27983 that the earlier fix did not cover, because that fix only detached streams still tracked in the session. This vulnerability affects Node.js 26.x (since 26.9.0) and 24.x (since 24.22.0)."}]}], "credits": [{"lang": "en", "value": "Chris Rohlf in collaboration with Claude and Anthropic Research", "type": "reporter"}, {"lang": "en", "value": "mcollina", "type": "remediation developer"}, {"lang": "en", "value": "UlisesGascon", "type": "remediation reviewer"}, {"lang": "en", "value": "pimterry", "type": "remediation reviewer"}, {"lang": "en", "value": "ronag", "type": "remediation reviewer"}, {"lang": "en", "value": "aduh95", "type": "coordinator"}], "affected": [{"vendor": "nodejs", "product": "node", "defaultStatus": "unaffected", "versions": [{"version": "24.0.0", "status": "affected", "lessThan": "24.22.3", "versionType": "semver"}, {"version": "25.0.0", "status": "affected", "lessThan": "26.13.1", "versionType": "semver"}]}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-617", "description": "Reachable Assertion"}]}], "metrics": [{"format": "CVSS", "cvssV3_0": {"version": "3.0", "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H", "baseScore": 8.2, "baseSeverity": "HIGH"}}], "references": [{"url": "https://nodejs.org/en/blog/vulnerability/november-2026-security-releases", "tags": ["vendor-advisory"]}, {"url": "https://cna.openjsf.org/security-advisories.html"}], "x_generator": {"engine": "nodejs-private/security-release publish-cves"}}}}

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{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "node", "vendor": "nodejs", "versions": [{"lessThan": "24.22.3", "status": "affected", "version": "24.0.0", "versionType": "semver"}, {"lessThan": "26.13.1", "status": "affected", "version": "25.0.0", "versionType": "semver"}]}], "source": "ce714d77-add3-4f53-aff5-83d477b104bb"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "A reachable assertion in Node.js HTTP/2 session teardown lets any unauthenticated client abort the server, over both TLS and cleartext. A client can arrange for an Http2Stream that still holds nghttp2-allocated header buffers to outlive its session: the stream is removed from the session's stream set but never detached, so when ~Http2Session() runs the memory accounting is nonzero and the CHECK_EQ(current_nghttp2_memory_, 0) assertion fails, terminating the process. The trigger needs only a default http2 server whose handler responds before the request body has ended, which is typical. It is a variant of CVE-2024-27983 that the earlier fix did not cover, because that fix only detached streams still tracked in the session. This vulnerability affects Node.js 26.x (since 26.9.0) and 24.x (since 24.22.0)."}], "id": "CVE-2026-123863", "lastModified": "2026-11-11T19:17:32.577", "metrics": {"cvssMetricV30": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.2, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H", "version": "3.0"}, "exploitabilityScore": 3.9, "impactScore": 4.2, "source": "ce714d77-add3-4f53-aff5-83d477b104bb", "type": "Secondary"}]}, "published": "2026-11-11T19:17:32.577", "references": [{"source": "ce714d77-add3-4f53-aff5-83d477b104bb", "url": "https://cna.openjsf.org/security-advisories.html"}, {"source": "ce714d77-add3-4f53-aff5-83d477b104bb", "url": "https://nodejs.org/en/blog/vulnerability/november-2026-security-releases"}], "sourceIdentifier": "ce714d77-add3-4f53-aff5-83d477b104bb", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-617"}], "source": "ce714d77-add3-4f53-aff5-83d477b104bb", "type": "Secondary"}]}

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