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.
CVE-2025-31137
HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence
This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.1%, top 73% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: epss, nvd
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 7.5Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 7.5
- EG Score
- 7.5(medium)
- EPSS
- 63.1%
- KEV
- Not listed
Published
April 1, 2025
Last Modified
April 15, 2026
References (1)
- security-advisories@githubhttps://github.com/remix-run/react-router/security/advisories/GHSA-4q56-crqp-v477
Affected Packages
(2 across 1 ecosystem)
npm(2)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| @react-router/express | — | 7.4.1 | — |
| @remix-run/express | — | 2.16.3 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Frequently asked(5)
What is CVE-2025-31137?
CVE-2025-31137 is a high vulnerability published on April 1, 2025. 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…
When was CVE-2025-31137 disclosed?
CVE-2025-31137 was first published in the National Vulnerability Database on April 1, 2025, with the most recent update on April 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2025-31137 actively exploited?
CVE-2025-31137 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 63.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2025-31137?
CVE-2025-31137 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2025-31137?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-31137, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2025-31137
Is Your Infrastructure Affected by CVE-2025-31137?
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