lostisland faraday up to 2.14.2 build_exclusive_url server-side request forgery

Summaryinfo

A vulnerability has been found in lostisland faraday up to 2.14.2 and classified as critical. This issue affects the function build_exclusive_url. Performing a manipulation results in server-side request forgery. This vulnerability is identified as CVE-2026-33637. The attack can be initiated remotely. There is not any exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in lostisland faraday up to 2.14.2. It has been classified as critical. This affects the function build_exclusive_url. The manipulation with an unknown input leads to a server-side request forgery vulnerability. CWE is classifying the issue as CWE-918. The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

Faraday is an HTTP client library abstraction layer that provides a common interface over many adapters. Versions 2.0.0 through 2.14.1 still allow protocol-relative host override when the request target is passed as a URI object (rather than a String) to Faraday::Connection#build_exclusive_url. This bypasses the February 2026 fix for GHSA-33mh-2634-fwr2 and enables off-host request forgery: a request built from a fixed-base Faraday::Connection can be redirected to an attacker-controlled host, forwarding connection-scoped values such as Authorization headers and default query parameters. This issue has been fixed in version 2.14.3.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-33637 since 03/23/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 316391 (Linux Distros Unpatched Vulnerability : CVE-2026-33637), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.0.0, 2.14.1 or 2.14.3 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (316391). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Vendor

• lostisland

Name

• faraday

Version

• 2.14.0
• 2.14.1
• 2.14.2

Website

• Product: https://github.com/lostisland/faraday/

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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