Vulnerability Intelligence Report
fastify-reply-from bypass of reply forwarding
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 specific routes in @fastify/reply-from. This vulnerability is fixed in 12.5.0.
No Active Exploit Signals
CVSS Base Score
6.9
MEDIUM
EPSS Probability:0.15%
Executive Threat Verdict
Evaluating...
Evaluating Threat Landscape...
Assessing known weaponization, exploitation telemetry, and federal advisories.
Attack Surface
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Authentication
—
Weaponization
—
SSVC Action
—
Weaknesses (CWE)
CWE-441 ↗CWE-441: Unintended Proxy or Intermediary ('Confused Deputy')
Affected Products & Versions
| Vendor | Product | Affected Versions |
|---|---|---|
| fastify | fastify-reply-from | < 12.5.0 (affected) |
References & Technical Advisories
No reference links found.
Threat Intelligence Signals
EPSS Score
0.147%
GitHub Advisory
Identity & Timeline
| Status | PUBLISHED |
| Assigning Authority | GitHub, Inc. · Vendor · USA |
| Reserved | 2025-11-28T23:33:56 |
| Published | 2025-12-01T22:39:32 |
| Last Updated | 2025-12-02T14:13:45 |
Community Chatter & Buzz