{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-120216", "assignerOrgId": "ce714d77-add3-4f53-aff5-83d477b104bb", "state": "PUBLISHED", "assignerShortName": "openjs", "dateReserved": "2026-10-31T16:06:34.967Z", "datePublished": "2026-11-02T11:08:00.038Z", "dateUpdated": "2026-11-02T11:08:00.038Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "ce714d77-add3-4f53-aff5-83d477b104bb", "shortName": "openjs", "dateUpdated": "2026-11-02T11:08:00.038Z"}, "descriptions": [{"lang": "en", "value": "fastify is a web framework for Node.js. In versions 5.8.0 through 5.12.7, when the server is configured with a nonzero handlerTimeout and a route returns a streaming response, a request whose stream has already sent its headers but stays open past the timeout crashes the server. When the timeout fires, Fastify tries to send a new error response on a response that has already started, raising an uncaught ERR_HTTP_HEADERS_SENT that terminates the Node.js process and interrupts any other in-flight requests. An unauthenticated remote client can trigger this with a single request to an affected streaming endpoint, so the impact is availability only, and exploitation requires the non-default handlerTimeout to be set. The default handlerTimeout of 0 is not affected. The issue is fixed in fastify 5.12.8, and users should upgrade to 5.12.8 or later. As a workaround, set handlerTimeout to 0, which disables the affected timeout path.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "fastify is a web framework for Node.js. In versions 5.8.0 through 5.12.7, when the server is configured with a nonzero handlerTimeout and a route returns a streaming response, a request whose stream has already sent its headers but stays open past the timeout crashes the server. When the timeout fires, Fastify tries to send a new error response on a response that has already started, raising an uncaught ERR_HTTP_HEADERS_SENT that terminates the Node.js process and interrupts any other in-flight requests. An unauthenticated remote client can trigger this with a single request to an affected streaming endpoint, so the impact is availability only, and exploitation requires the non-default handlerTimeout to be set. The default handlerTimeout of 0 is not affected. The issue is fixed in fastify 5.12.8, and users should upgrade to 5.12.8 or later. As a workaround, set handlerTimeout to 0, which disables the affected timeout path."}]}], "affected": [{"vendor": "fastify", "product": "fastify", "defaultStatus": "unaffected", "versions": [{"versionType": "semver", "status": "affected", "version": "5.8.0", "lessThan": "5.12.8"}, {"versionType": "semver", "status": "unaffected", "version": "5.12.8"}], "packageURL": "pkg:npm/fastify"}], "references": [{"url": "https://github.com/fastify/fastify/security/advisories/GHSA-3qgw-9275-xf8w"}, {"url": "https://cna.openjsf.org/security-advisories.html"}], "credits": [{"lang": "en", "type": "reporter", "value": "SLRHR"}, {"lang": "en", "type": "remediation developer", "value": "mcollina"}, {"lang": "en", "type": "remediation developer", "value": "UlisesGascon"}], "title": "fastify vulnerable to Denial of Service via uncaught exception on handlerTimeout with streaming responses", "metrics": [{"format": "CVSS", "cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.9, "baseSeverity": "MEDIUM"}, "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "problemTypes": [{"descriptions": [{"cweId": "CWE-248", "lang": "en", "description": "CWE-248: Uncaught Exception", "type": "CWE"}]}], "x_generator": {"engine": "cve-kit 1.0.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "packageURL": "pkg:npm/fastify", "product": "fastify", "vendor": "fastify", "versions": [{"lessThan": "5.12.8", "status": "affected", "version": "5.8.0", "versionType": "semver"}, {"status": "unaffected", "version": "5.12.8", "versionType": "semver"}]}], "source": "ce714d77-add3-4f53-aff5-83d477b104bb"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "fastify is a web framework for Node.js. In versions 5.8.0 through 5.12.7, when the server is configured with a nonzero handlerTimeout and a route returns a streaming response, a request whose stream has already sent its headers but stays open past the timeout crashes the server. When the timeout fires, Fastify tries to send a new error response on a response that has already started, raising an uncaught ERR_HTTP_HEADERS_SENT that terminates the Node.js process and interrupts any other in-flight requests. An unauthenticated remote client can trigger this with a single request to an affected streaming endpoint, so the impact is availability only, and exploitation requires the non-default handlerTimeout to be set. The default handlerTimeout of 0 is not affected. The issue is fixed in fastify 5.12.8, and users should upgrade to 5.12.8 or later. As a workaround, set handlerTimeout to 0, which disables the affected timeout path."}], "id": "CVE-2026-120216", "lastModified": "2026-11-02T11:17:31.553", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 5.9, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 2.2, "impactScore": 3.6, "source": "ce714d77-add3-4f53-aff5-83d477b104bb", "type": "Secondary"}]}, "published": "2026-11-02T11:17:31.553", "references": [{"source": "ce714d77-add3-4f53-aff5-83d477b104bb", "url": "https://cna.openjsf.org/security-advisories.html"}, {"source": "ce714d77-add3-4f53-aff5-83d477b104bb", "url": "https://github.com/fastify/fastify/security/advisories/GHSA-3qgw-9275-xf8w"}], "sourceIdentifier": "ce714d77-add3-4f53-aff5-83d477b104bb", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-248"}], "source": "ce714d77-add3-4f53-aff5-83d477b104bb", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[5.8.0,5.12.8)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "5.12.8"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "fastify", "source": "cna", "vendor": "fastify"}, "product": "fastify", "vendor": "fastify"}], "created": "2026-11-02T12:30:14.533033+00:00", "updated": "2026-11-02T12:30:15.027680+00:00", "vendors": ["fastify", "fastify$PRODUCT$fastify"]}