CVE-2025-66415
published 2025-12-01CVE-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…
PriorityP430medium5.4CVSS 3.1
AVNACLPRNUIRSUCLILAN
EPSS
0.15%
4.8th percentile
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.
Affected
3 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| fastify | fastify-reply-from | < 12.5.0 | 12.5.0 |
| fastify | reply-from | <= 12.4.0 | — |
| fastify | reply-from | >= 0 < 12.5.0 | 12.5.0 |
CVSS provenance
nvdv3.15.4MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
nvdv4.06.9MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
vendor_redhat6.9MEDIUM
Stop checking back — get the weekly exploitation signal.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
GHSA
fastify-reply-from affected by bypass of reply forwarding
ghsa·2025-12-02
CVE-2025-66415 [MEDIUM] CWE-441 fastify-reply-from affected by bypass of reply forwarding
fastify-reply-from affected by bypass of reply forwarding
### Summary
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`.
### Details
An attacker can bypass the route defined by the `@fastify/reply-from` package by adding a `..` symbol, which, for `curl` version `8.7.1`, is `%2e%2e`.
### Impact
Everyone is using this package with the routes option to protect a 3rd-party resource.
OSV
fastify-reply-from affected by bypass of reply forwarding
osv·2025-12-02
CVE-2025-66415 [MEDIUM] fastify-reply-from affected by bypass of reply forwarding
fastify-reply-from affected by bypass of reply forwarding
### Summary
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`.
### Details
An attacker can bypass the route defined by the `@fastify/reply-from` package by adding a `..` symbol, which, for `curl` version `8.7.1`, is `%2e%2e`.
### Impact
Everyone is using this package with the routes option to protect a 3rd-party resource.
Red Hat
fastify-reply-from: fastify-reply-from: Unauthorized route access via malicious URL
vendor_redhat·2025-12-01·CVSS 6.9
CVE-2025-66415 [MEDIUM] CWE-441 fastify-reply-from: fastify-reply-from: Unauthorized route access via malicious URL
fastify-reply-from: fastify-reply-from: Unauthorized route access via malicious URL
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.
A flaw was found in fastify-reply-from. This vulnerability allows an attacker to bypass intended route restrictions and gain unauthorized access to specific application routes, potentially exposing sensitive information or functionality, via crafting a malicious Uniform Resource Locator (URL).
Statement: This vulnerability is rated Moderate for Red Hat because it allows an attacker to bypass int
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
2025-12-01
Published