Vulnerability in Fastify Fastify-reply-from
CVE-2025-66415
fastify-reply-from is a Fastify plugin to forward the current HTTP request to another server. Prior to 12.5.0, by crafting a malicious URL, an attacker could access routes that are not allowed, even though the reply.from is defined for spe…
EPSS: 0.002 (4.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N.
Affected products
- Fastify Fastify-reply-from — versions < 12.5.0
- Fastify Reply-from
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
Frequently asked questions
- What is CVE-2025-66415?
- CVE-2025-66415 is a medium-severity vulnerability in Fastify Fastify-reply-from, classified under Unintended Proxy or Intermediary (Confused Deputy). CVSS score: 5.4/10. Published 2025-12-01.
- How severe is CVE-2025-66415?
- Medium severity. CVSS v3 base score is 5.4 out of 10.