{"schema":"threatline.record/2","record":{"id":"CVE-2026-92081","aliases":["GHSA-4mh8-r7rc-xpvc"],"summary":"fastify vulnerable to Denial of Service via unhandled exception on HTTP/2 trailer responses","details":"### Impact\n\n`fastify` crashes with an uncaught `ERR_HTTP2_INVALID_CONNECTION_HEADERS` exception when a route that registers a response trailer via `reply.trailer()` is served over HTTP/2. Fastify unconditionally adds the `Transfer-Encoding: chunked` header when a trailer is set, which is forbidden on HTTP/2, so Node.js throws while serializing the response headers. The exception is not caught and becomes an uncaughtException, terminating the Node.js process.\n\nOne unauthenticated HTTP/2 request to any route that uses trailers is enough to crash the server, dropping all in-flight requests, and the request can be repeated to keep the process down. Applications are affected only when HTTP/2 is enabled (`http2: true`) and at least one route registers a trailer. HTTP/1.x responses are not affected.\n\n### Patches\n\nUpgrade to `fastify` `5.12.5` or later.\n\n### Workarounds\n\nAvoid registering response trailers with `reply.trailer()` on routes served over HTTP/2 until upgrading.","categories":["Frameworks"],"product":"fastify","vendor":"fastify","ecosystem":"npm","affected_ranges":[{"source":"GitHub Advisory Database","source_url":"https://github.com/advisories/GHSA-4mh8-r7rc-xpvc","source_modified_at":"2026-09-30T23:53:45Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"ecosystem":"npm","name":"fastify"},"range":"< 5.12.5"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-92081","source_modified_at":"2026-09-16T14:00:59.305Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"fastify","vendor":"fastify","versions":[{"versionType":"semver","status":"affected","version":"0","lessThan":"5.12.5"},{"versionType":"semver","status":"unaffected","version":"5.12.5"}],"defaultStatus":"unaffected"},{"source":"OSV","source_url":"https://osv.dev/vulnerability/GHSA-4mh8-r7rc-xpvc","source_modified_at":"2026-10-01T00:00:05.778371686Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"fastify","ecosystem":"npm","purl":"pkg:npm/fastify"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"5.12.5"}]}],"versions":[]}],"fixed_versions":[{"source":"GitHub Advisory Database","source_url":"https://github.com/advisories/GHSA-4mh8-r7rc-xpvc","source_modified_at":"2026-09-30T23:53:45Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"ecosystem":"npm","name":"fastify"},"version":"5.12.5"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-92081","source_modified_at":"2026-09-16T14:00:59.305Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"fastify","ecosystem":null},"version":"5.12.5","basis":"first unaffected version stated in the CVE record"},{"source":"OSV","source_url":"https://osv.dev/vulnerability/GHSA-4mh8-r7rc-xpvc","source_modified_at":"2026-10-01T00:00:05.778371686Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"fastify","ecosystem":"npm","purl":"pkg:npm/fastify"},"version":"5.12.5"}],"cvss":5.9,"severity":"Medium","kev":{"listed":false},"epss":{"probability":0.00412,"percentile":0.34398,"score_date":"2026-10-23"},"published_at":"2026-09-16T08:52:49.757Z","modified_at":"2026-10-01T00:00:05.778371686Z","provenance":[{"source":"GitHub Advisory Database","url":"https://github.com/advisories/GHSA-4mh8-r7rc-xpvc","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-09-30T23:53:45Z"},{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-92081","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-09-16T14:00:59.305Z"},{"source":"OSV","url":"https://osv.dev/vulnerability/GHSA-4mh8-r7rc-xpvc","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-01T00:00:05.778371686Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-92081","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/fastify/fastify/security/advisories/GHSA-4mh8-r7rc-xpvc"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-92081","source":"GitHub Advisory Database"},{"url":"https://github.com/fastify/fastify/issues/6574","source":"GitHub Advisory Database"},{"url":"https://github.com/fastify/fastify/commit/ad06a4c3fe8a944a904f38068249b18b8f552e90","source":"GitHub Advisory Database"},{"source":"CVE List","url":"https://cna.openjsf.org/security-advisories.html"},{"url":"https://github.com/fastify/fastify/releases/tag/v5.12.5","source":"GitHub Advisory Database"},{"url":"https://github.com/advisories/GHSA-4mh8-r7rc-xpvc","source":"GitHub Advisory Database"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","ssvc":{"exploitation":"none","automatable":"no","technical_impact":"partial","assessed_at":"2026-09-16T14:00:06.966478Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-01T00:00:05.778371686Z","content_hash":"45c70d34c9239b5a89dbf3397991a682c5579fa63eb6cb8af58ea6fc085d075a"}}