remix-run react-router up to 6.30.3/7.14.0 Relative URL redirect

Summaryinfo

A vulnerability was found in remix-run react-router up to 6.30.3/7.14.0. It has been rated as problematic. The impacted element is the function redirect of the component Relative URL Handler. Performing a manipulation results in redirect. This vulnerability is reported as CVE-2026-40181. The attack is possible to be carried out remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as problematic, was found in remix-run react-router up to 6.30.3/7.14.0. This affects the function redirect of the component Relative URL Handler. The manipulation with an unknown input leads to a redirect vulnerability. CWE is classifying the issue as CWE-601. A web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a Redirect. This simplifies phishing attacks. This is going to have an impact on integrity. The summary by CVE is:

React Router is a router for React. In versions 7.0.0 through 7.14.0 and 6.7.0 through 6.30.3, certain URLs passed to the redirect function can trigger an open redirect to an external domain due to path values starting with // being reinterpreted as protocol-relative URLs. The level of impact depends on the validation done by the application prior to returning the redirect. This does not impact applications using Declarative Mode (). This is patched in versions 7.14.1 and 6.30.4.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-40181 since 04/09/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1204.001 according to MITRE ATT&CK.

Upgrading to version 6.30.4 or 7.14.1 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-33996). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• Router Operating System

Vendor

• remix-run

Name

• react-router

Version

• 6.30.0
• 6.30.1
• 6.30.2
• 6.30.3
• 7.0
• 7.1
• 7.2
• 7.3
• 7.4
• 7.5
• 7.6
• 7.7
• 7.8
• 7.9
• 7.10
• 7.11
• 7.12
• 7.13
• 7.14.0

Website

• Product: https://github.com/remix-run/react-router/

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

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