Improper Handling of Exceptional Conditions Affecting @react-router/dev package, versions >=7.2.0 <7.5.2
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JS-REACTROUTERDEV-9804421
- published25 Apr 2025
- disclosed24 Apr 2025
- creditRachid Allam, Yasser Allam
Introduced: 24 Apr 2025
NewCVE-2025-43864 (opens in a new tab)How to fix?
Upgrade @react-router/dev to version 7.5.2 or higher.
Overview
@react-router/dev is a Dev tools and CLI for React Router
Affected versions of this package are vulnerable to Improper Handling of Exceptional Conditions via the X-React-Router-SPA-Mode header. An attacker can disrupt the availability of the application by sending a crafted request that forces the server to switch to SPA mode, leading to an error that corrupts the page content.
Note:
This is only exploitable if the application is running in Framework mode, which is the default configuration, it has a caching system in place and the target page utilizes a loader.