HIGH

CVE-2025-31137

CVSS v3

7.5

HIGH

EPSS Score

1.2 %

exploit probability, as of 2026-09-25

CISA KEV

known exploited

Exploitation

—

SSVC status

Description

React Router is a multi-strategy router for React bridging the gap from React 18 to React 19. There is a vulnerability in Remix/React Router that affects all Remix 2 and React Router 7 consumers using the Express adapter. Basically, this vulnerability allows anyone to spoof the URL used in an incoming Request by putting a URL pathname in the port section of a URL that is part of a Host or X-Forwarded-Host header sent to a Remix/React Router request handler. This issue has been patched and released in Remix 2.16.3 and React Router 7.4.1.

Technical details

Published: 2025-04-01

Frequently asked questions

What is CVE-2025-31137?

Is CVE-2025-31137 actively exploited?

Active exploitation of CVE-2025-31137 has not been confirmed. Its EPSS score was 1.2% on 2026-09-25, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2025-31137?

CVE-2025-31137 has a CVSS v3 base score of 7.5 (HIGH severity).

Is CVE-2025-31137 affecting your environment?

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