Resource exhaustion in Fastify
CVE-2026-25224
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.
EPSS: 0.005 (39.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 3.7 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L.
Affected products
- Fastify — versions < 5.7.3
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Permissions Required, x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-25224?
- CVE-2026-25224 is a low-severity vulnerability in Fastify, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 3.7/10. Published 2026-02-03.
- How severe is CVE-2026-25224?
- Low severity. CVSS v3 base score is 3.7 out of 10.