CVE-2026-25765CWE-918

Faraday affected by SSRF via protocol-relative URL host override in build_exclusive_url

Medium · published February 9, 2026

CVSS v3.1
5.8
EPSS
0%
Percentile
37.8
In the wild
Unconfirmed
What it is

Faraday is an HTTP client library abstraction layer that provides a common interface over many adapters. Prior to 2.14.1, Faraday's build_exclusive_url method (in lib/faraday/connection.rb) uses Ruby's URI#merge to combine the connection's base URL with a user-supplied path. Per RFC 3986, protocol-relative URLs (e.g. //evil.com/path) are treated as network-path references that override the base URL's host/authority component. This means that if any application passes user-controlled input to Faraday's get(), post(), build_url(), or other request methods, an attacker can supply a protocol-relative URL like //attacker.com/endpoint to redirect the request to an arbitrary host, enabling Server-Side Request Forgery (SSRF). This vulnerability is fixed in 2.14.1.

The record
Technical detail
CVSS v3.1
5.8 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N
CVSS v4.0
Not supplied
EPSS
0.00446 · 37.8th percentile
Weakness
CWE-918 · Server-Side Request Forgery (SSRF)
Published
2026-02-09T20:30Z
EPSS history
Timeline
  • 09 FEB 20:30Z
    Faraday affected by SSRF via protocol-relative URL host override in build_exclusive_url
    cvelistv5