CVE-2025-66415
mediumpriority · track · 22EPSS 0.002 · 7 %ileEUUSEPSS · scored 2026-10-24
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.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 2.7–6.9
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (3)
Products and version ranges known to be affected.
advisories (1)
Vendor and ecosystem advisories describing this.
- GHSA-2q7r-29rg-6m5hfastify-reply-from affected by bypass of reply forwarding2025-12-02ghsa · osvUS
### 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.
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (8)
External citations — patches, advisories, analysis.
- https://access.redhat.com/security/cve/cve-2025-66415cnnvd
- https://github.com/fastify/fastify-reply-from/commit/4d9795cd5b57a36756d37b7f036eae369f69fa66cnnvd
- https://github.com/fastify/fastify-reply-from/releasesPatchcnnvd
- https://github.com/fastify/fastify-reply-from/security/advisories/GHSA-2q7r-29rg-6m5hcnnvd
- https://github.com/fastify/fastify-reply-from/commit/4d9795cd5b57a36756d37b7f036eae369f69fa66enisa_euvd
- https://github.com/fastify/fastify-reply-from/security/advisories/GHSA-2q7r-29rg-6m5henisa_euvd
- https://github.com/fastify/fastify-reply-from/commit/4d9795cd5b57a36756d37b7f036eae369f69fa66Patchnvd
- https://github.com/fastify/fastify-reply-from/security/advisories/GHSA-2q7r-29rg-6m5hVendor Advisorynvd
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