Resource exhaustion in React Router - CVE-2026-55685
Published: July 22, 2026
Vulnerability identifier: #VU139178
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:A/AC:L/AT:P/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-55685
CWE-ID: CWE-400
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vendor: Remix
Affected software:
React Router
React Router
Detailed vulnerability description
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to uncontrolled resource consumption in the __manifest endpoint when handling targeted unauthenticated requests. A remote user can send targeted requests to cause a denial of service.
Only Framework Mode applications are vulnerable.
How to mitigate CVE-2026-55685
Install security update from vendor's website.