{"schema":"threatline.record/2","record":{"id":"CVE-2026-19534","aliases":["GHSA-rfgv-xxqx-mfg5"],"summary":"undici vulnerable to Denial of Service via unrequested WebSocket subprotocol","details":"### Impact\n\nThe undici WebSocket client throws an uncaught `TypeError` during the opening handshake when a server's `101` response includes a `Sec-WebSocket-Protocol` header that the client never requested. The throw occurs in a `queueMicrotask` callback with no surrounding `try`/`catch`, so it propagates as an uncaught exception and terminates the Node.js process. This is a remote, unauthenticated denial of service against any application that opens a WebSocket to an attacker controlled or compromised server, or over a plaintext `ws://` connection subject to a machine-in-the-middle. It affects the default `new WebSocket(url)` usage, where no subprotocol is requested. Per RFC 6455 section 4.1, an unrequested subprotocol must fail the connection, not crash it.\n\nAll releases starting at undici 6.7.0 are affected.\n\n### Patches\n\nUpgrade to undici 6.28.1, 7.29.1, or 8.10.2.\n\n### Workarounds\n\nNo workaround is available. The fix must be applied through an upgrade.","categories":["Libraries & packages"],"product":"undici","vendor":"undici","ecosystem":"npm","affected_ranges":[{"source":"GitHub Advisory Database","source_url":"https://github.com/advisories/GHSA-rfgv-xxqx-mfg5","source_modified_at":"2026-09-29T18:21:41Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"ecosystem":"npm","name":"undici"},"range":">= 6.7.0, < 6.28.1"},{"source":"GitHub Advisory Database","source_url":"https://github.com/advisories/GHSA-rfgv-xxqx-mfg5","source_modified_at":"2026-09-29T18:21:41Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"ecosystem":"npm","name":"undici"},"range":">= 7.0.0, < 7.29.1"},{"source":"GitHub Advisory Database","source_url":"https://github.com/advisories/GHSA-rfgv-xxqx-mfg5","source_modified_at":"2026-09-29T18:21:41Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"ecosystem":"npm","name":"undici"},"range":">= 8.0.0, < 8.10.2"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-19534","source_modified_at":"2026-09-04T18:18:31.205Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"undici","vendor":"undici","versions":[{"versionType":"semver","status":"affected","version":"6.7.0","lessThan":"6.28.1"},{"versionType":"semver","status":"unaffected","version":"6.28.1"},{"versionType":"semver","status":"affected","version":"7.0.0","lessThan":"7.29.1"},{"versionType":"semver","status":"unaffected","version":"7.29.1"},{"versionType":"semver","status":"affected","version":"8.0.0","lessThan":"8.10.2"},{"versionType":"semver","status":"unaffected","version":"8.10.2"}],"defaultStatus":"unaffected"},{"source":"OSV","source_url":"https://osv.dev/vulnerability/GHSA-rfgv-xxqx-mfg5","source_modified_at":"2026-09-29T18:30:41.167602268Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"undici","ecosystem":"npm","purl":"pkg:npm/undici"},"ranges":[{"type":"SEMVER","events":[{"introduced":"6.7.0"},{"fixed":"6.28.1"}]}],"versions":[]},{"source":"OSV","source_url":"https://osv.dev/vulnerability/GHSA-rfgv-xxqx-mfg5","source_modified_at":"2026-09-29T18:30:41.167602268Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"undici","ecosystem":"npm","purl":"pkg:npm/undici"},"ranges":[{"type":"SEMVER","events":[{"introduced":"7.0.0"},{"fixed":"7.29.1"}]}],"versions":[]},{"source":"OSV","source_url":"https://osv.dev/vulnerability/GHSA-rfgv-xxqx-mfg5","source_modified_at":"2026-09-29T18:30:41.167602268Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"undici","ecosystem":"npm","purl":"pkg:npm/undici"},"ranges":[{"type":"SEMVER","events":[{"introduced":"8.0.0"},{"fixed":"8.10.2"}]}],"versions":[]}],"fixed_versions":[{"source":"GitHub Advisory Database","source_url":"https://github.com/advisories/GHSA-rfgv-xxqx-mfg5","source_modified_at":"2026-09-29T18:21:41Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"ecosystem":"npm","name":"undici"},"version":"6.28.1"},{"source":"GitHub Advisory Database","source_url":"https://github.com/advisories/GHSA-rfgv-xxqx-mfg5","source_modified_at":"2026-09-29T18:21:41Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"ecosystem":"npm","name":"undici"},"version":"7.29.1"},{"source":"GitHub Advisory Database","source_url":"https://github.com/advisories/GHSA-rfgv-xxqx-mfg5","source_modified_at":"2026-09-29T18:21:41Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"ecosystem":"npm","name":"undici"},"version":"8.10.2"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-19534","source_modified_at":"2026-09-04T18:18:31.205Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"undici","ecosystem":null},"version":"6.28.1","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-19534","source_modified_at":"2026-09-04T18:18:31.205Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"undici","ecosystem":null},"version":"7.29.1","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-19534","source_modified_at":"2026-09-04T18:18:31.205Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"undici","ecosystem":null},"version":"8.10.2","basis":"first unaffected version stated in the CVE record"},{"source":"OSV","source_url":"https://osv.dev/vulnerability/GHSA-rfgv-xxqx-mfg5","source_modified_at":"2026-09-29T18:30:41.167602268Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"undici","ecosystem":"npm","purl":"pkg:npm/undici"},"version":"6.28.1"},{"source":"OSV","source_url":"https://osv.dev/vulnerability/GHSA-rfgv-xxqx-mfg5","source_modified_at":"2026-09-29T18:30:41.167602268Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"undici","ecosystem":"npm","purl":"pkg:npm/undici"},"version":"7.29.1"},{"source":"OSV","source_url":"https://osv.dev/vulnerability/GHSA-rfgv-xxqx-mfg5","source_modified_at":"2026-09-29T18:30:41.167602268Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"undici","ecosystem":"npm","purl":"pkg:npm/undici"},"version":"8.10.2"}],"cvss":7.5,"severity":"High","kev":{"listed":false},"epss":{"probability":0.00394,"percentile":0.32424,"score_date":"2026-10-23"},"published_at":"2026-09-04T17:10:05.081Z","modified_at":"2026-09-29T18:30:41.167602268Z","provenance":[{"source":"GitHub Advisory Database","url":"https://github.com/advisories/GHSA-rfgv-xxqx-mfg5","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-09-29T18:21:41Z"},{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-19534","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-09-04T18:18:31.205Z"},{"source":"OSV","url":"https://osv.dev/vulnerability/GHSA-rfgv-xxqx-mfg5","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-09-29T18:30:41.167602268Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-19534","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["GitHub Advisory Database","CVE List","OSV","EPSS"],"references":[{"source":"CVE List","url":"https://github.com/nodejs/undici/security/advisories/GHSA-rfgv-xxqx-mfg5"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-19534","source":"GitHub Advisory Database"},{"url":"https://github.com/nodejs/undici/commit/2af0faf88b906d3127a360c3ac75164c0f95e5a5","source":"GitHub Advisory Database"},{"url":"https://github.com/nodejs/undici/commit/6615e0175e9b635bcd2e3e87a47daa82f6f5b728","source":"GitHub Advisory Database"},{"url":"https://github.com/nodejs/undici/commit/66e12816064cf3068f63bd134748b7fc4e779bad","source":"GitHub Advisory Database"},{"source":"CVE List","url":"https://cna.openjsf.org/security-advisories.html"},{"url":"https://github.com/nodejs/undici/releases/tag/v6.28.1","source":"GitHub Advisory Database"},{"url":"https://github.com/nodejs/undici/releases/tag/v7.29.1","source":"GitHub Advisory Database"},{"url":"https://github.com/nodejs/undici/releases/tag/v8.10.2","source":"GitHub Advisory Database"},{"url":"https://github.com/advisories/GHSA-rfgv-xxqx-mfg5","source":"GitHub Advisory Database"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","ssvc":{"exploitation":"none","automatable":"yes","technical_impact":"partial","assessed_at":"2026-09-04T18:18:18.694757Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"ecosystem","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-09-29T18:30:41.167602268Z","content_hash":"eadf37d3170b7b5fce8257ce53f1492ef510ad7a45409f02253aa456fedbb8c2"}}