{"id":"CVE-2026-25224","aliases":["CLSA-2026-1772669615","CLSA-2026-1773620080","CLSA-2026-1790110789","EUVD-2026-5158","GHSA-mrq3-vjjr-p77c"],"status":"published","title":"Fastify Vulnerable to DoS via Unbounded Memory Allocation in sendWebStream","description":"Fastify is a fast and low overhead web framework, for Node.js. Prior to version 5.7.3, a denial-of-service vulnerability in Fastify’s Web Streams response handling can allow a remote client to exhaust server memory. Applications that return a ReadableStream (or Response with a Web Stream body) via reply.send() are impacted. A slow or non-reading client can trigger unbounded buffering when backpressure is ignored, leading to process crashes or severe degradation. This issue has been patched in version 5.7.3.","severity":{"version":"3.1","score":3.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"low","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-08","score":0.00546,"percentile":0.46035,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-770"],"published":"2026-02-02T22:25:05Z","modified":"2026-10-28T02:31:08Z","fixes":[{"ecosystem":"npm","package":"fastify","fixed_in":["5.7.3"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"fastify","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"5.7.2"},{"fixed":"5.7.3"}]}]},{"source":"osv","ecosystem":"TuxCare:npm","package":"fastify","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.29.1-tuxcare.0"},{"fixed":"4.29.1-tuxcare.1"}]}],"versions":["4.29.1"],"bundled":2},{"source":"osv","ecosystem":"TuxCare:npm","package":"fastify","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.29.5-tuxcare.0"},{"fixed":"3.29.5-tuxcare.3"}]}],"versions":["3.29.5","3.29.5-tuxcare.1","3.29.5-tuxcare.2"],"bundled":2},{"source":"osv","ecosystem":"TuxCare:npm","package":"fastify","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.2.1-tuxcare.0"},{"fixed":"5.2.1-tuxcare.2"}]}],"versions":["5.2.1","5.2.1-tuxcare.1"],"bundled":3},{"source":"osv","ecosystem":"npm","package":"fastify","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"5.7.3"}]}]}],"products":[{"vendor":"@clerk","product":"fastify"},{"vendor":"fastify","product":"fastify"}],"references":[{"url":"https://github.com/fastify/fastify/security/advisories/GHSA-mrq3-vjjr-p77c","tags":["x_refsource_CONFIRM","Vendor Advisory","advisory","web"]},{"url":"https://github.com/fastify/fastify/commit/eb11156396f6a5fedaceed0140aed2b7f026be37","tags":["x_refsource_MISC","Patch","fix","web"]},{"url":"https://hackerone.com/reports/3524779","tags":["x_refsource_MISC","Permissions Required","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-25224","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-mrq3-vjjr-p77c"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/25xxx/CVE-2026-25224.json","tags":["advisory"]},{"url":"https://github.com/fastify/fastify","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-25224","title":"Fastify Vulnerable to DoS via Unbounded Memory Allocation in sendWebStream","description":"Fastify is a fast and low overhead web framework, for Node.js. Prior to version 5.7.3, a denial-of-service vulnerability in Fastify’s Web Streams response handling can allow a remote client to exhaust server memory. Applications that return a ReadableStream (or Response with a Web Stream body) via reply.send() are impacted. A slow or non-reading client can trigger unbounded buffering when backpressure is ignored, leading to process crashes or severe degradation. This issue has been patched in version 5.7.3.","status":"published","published":"2026-02-03T21:21:35.437Z","modified":"2026-02-04T16:20:32.845Z","cvss":[{"version":"3.1","score":3.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"low","assessor":"cna"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T13:41:30.911526Z"}],"euvd":[{"id":"EUVD-2026-5158","description":"Fastify is a fast and low overhead web framework, for Node.js. Prior to version 5.7.3, a denial-of-service vulnerability in Fastify’s Web Streams response handling can allow a remote client to exhaust server memory. Applications that return a ReadableStream (or Response with a Web Stream body) via reply.send() are impacted. A slow or non-reading client can trigger unbounded buffering when backpressure is ignored, leading to process crashes or severe degradation. This issue has been patched in version 5.7.3.","status":"published","published":"2026-02-03T21:21:35Z","modified":"2026-02-04T16:20:32Z","cvss":[{"version":"3.1","score":3.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"low"}],"updated_at":"2026-11-02T19:48:44.193176Z"}],"ghsa":[{"id":"GHSA-mrq3-vjjr-p77c","title":"Fastify Vulnerable to DoS via Unbounded Memory Allocation in sendWebStream","description":"### Impact\nA Denial of Service vulnerability in Fastify’s Web Streams response handling can allow a remote client to exhaust server memory. Applications that return a `ReadableStream` (or `Response` with a Web Stream body) via `reply.send()` are impacted. A slow or non-reading client can trigger unbounded buffering when backpressure is ignored, leading to process crashes or severe degradation.\n\n### Patches\nThe issue is fixed in Fastify 5.7.3. Users should upgrade to 5.7.3 or later.\n\n### Workarounds\nAvoid sending Web Streams from Fastify responses (e.g., `ReadableStream` or `Response` bodies). Use Node.js streams (`stream.Readable`) or buffered payloads instead until the project can upgrade.\n\n### References\n- https://hackerone.com/reports/3524779","status":"published","published":"2026-02-02T22:25:05Z","modified":"2026-02-04T17:46:09Z","cvss":[{"version":"3.1","score":3.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"low"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T14:39:22.637668Z"}],"nvd":[{"id":"CVE-2026-25224","description":"Fastify is a fast and low overhead web framework, for Node.js. Prior to version 5.7.3, a denial-of-service vulnerability in Fastify’s Web Streams response handling can allow a remote client to exhaust server memory. Applications that return a ReadableStream (or Response with a Web Stream body) via reply.send() are impacted. A slow or non-reading client can trigger unbounded buffering when backpressure is ignored, leading to process crashes or severe degradation. This issue has been patched in version 5.7.3.","status":"published","published":"2026-02-03T22:16:31.29Z","modified":"2026-06-17T10:24:20.147Z","cvss":[{"version":"3.1","score":3.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"low","assessor":"secondary"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T14:12:05.149641Z"}],"osv":[{"id":"CVE-2026-25224","title":"Fastify Vulnerable to DoS via Unbounded Memory Allocation in sendWebStream","description":"Fastify is a fast and low overhead web framework, for Node.js. Prior to version 5.7.3, a denial-of-service vulnerability in Fastify’s Web Streams response handling can allow a remote client to exhaust server memory. Applications that return a ReadableStream (or Response with a Web Stream body) via reply.send() are impacted. A slow or non-reading client can trigger unbounded buffering when backpressure is ignored, leading to process crashes or severe degradation. This issue has been patched in version 5.7.3.","status":"published","published":"2026-02-03T21:21:35.437Z","modified":"2026-10-28T02:31:08.37145177Z","cvss":[{"version":"3.1","score":3.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"low"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T15:44:59.438965Z"},{"id":"GHSA-mrq3-vjjr-p77c","title":"Fastify Vulnerable to DoS via Unbounded Memory Allocation in sendWebStream","description":"### Impact\nA Denial of Service vulnerability in Fastify’s Web Streams response handling can allow a remote client to exhaust server memory. Applications that return a `ReadableStream` (or `Response` with a Web Stream body) via `reply.send()` are impacted. A slow or non-reading client can trigger unbounded buffering when backpressure is ignored, leading to process crashes or severe degradation.\n\n### Patches\nThe issue is fixed in Fastify 5.7.3. Users should upgrade to 5.7.3 or later.\n\n### Workarounds\nAvoid sending Web Streams from Fastify responses (e.g., `ReadableStream` or `Response` bodies). Use Node.js streams (`stream.Readable`) or buffered payloads instead until the project can upgrade.\n\n### References\n- https://hackerone.com/reports/3524779","status":"published","published":"2026-02-02T22:25:05Z","modified":"2026-02-04T18:08:54.461651Z","cvss":[{"version":"3.1","score":3.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"low"}],"cwes":["CWE-770"],"updated_at":"2026-11-02T15:46:52.170928Z"},{"id":"CLSA-2026-1772669615","title":"TuxCare security update for fastify (2 CVEs)","description":"TuxCare rebuilt fastify to address 2 CVEs. Fixed in 4.29.1-tuxcare.1.","status":"published","published":"2026-08-04T14:52:10Z","modified":"2026-10-15T09:45:27.086204798Z","updated_at":"2026-11-02T15:43:43.249928Z"},{"id":"CLSA-2026-1773620080","title":"TuxCare security update for fastify (2 CVEs)","description":"TuxCare rebuilt fastify to address 2 CVEs. Fixed in 3.29.5-tuxcare.3.","status":"published","published":"2026-08-04T14:52:11Z","modified":"2026-10-15T09:47:28.808600676Z","updated_at":"2026-11-02T15:43:43.621843Z"},{"id":"CLSA-2026-1790110789","title":"TuxCare security update for fastify (3 CVEs)","description":"TuxCare rebuilt fastify to address 3 CVEs. Fixed in 5.2.1-tuxcare.2.","status":"published","published":"2026-09-22T20:59:49Z","modified":"2026-10-15T09:45:34.375513006Z","updated_at":"2026-11-02T15:43:48.28229Z"}]}}