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

CVE-2025-31137 has a CVSS 3.0 base score of 7.5 (High). CVSS vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. EPSS exploitation probability: 0.1%.

Which versions of Red Hat are affected by CVE-2025-31137?

Organizations using React Router face notable risk from CVE-2025-31137 rated CVSS 7.5. Exploitation could compromise the security of affected deployments.. A patch is available.

How to fix or mitigate CVE-2025-31137?

Within 7 days: Identify all affected systems and apply vendor patches promptly. Monitor vendor channels for patch availability.

Red Hat CVE-2025-31137

HIGH

HTTP Request/Response Smuggling (CWE-444)

2025-04-01 security-advisories@github.com

Information Disclosure Request Smuggling Red Hat

7.5

CVSS 3.0 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

7.5 HIGH

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Red Hat

7.5 HIGH

qualitative

Primary rating from GitHub Advisory.

CVSS VectorGitHub Advisory

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Lifecycle Timeline

Patch released

Mar 31, 2026 - 21:13 nvd

Patch available

Analysis Generated

Mar 28, 2026 - 18:34 vuln.today

CVE Published

Apr 01, 2025 - 19:15 nvd

HIGH 7.5

Blast Radius

ecosystem impact

† from your stack dependencies † transitive graph · vuln.today resolves 4-path depth

1 npm packages depend on @react-router/express (1 direct, 0 indirect)
2 npm packages depend on @remix-run/express (1 direct, 1 indirect)

Ecosystem-wide dependent count for version 7.0.0 and other introduced versions.

DescriptionGitHub Advisory

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.

AnalysisAI

React Router is a multi-strategy router for React bridging the gap from React 18 to React 19. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.

Technical ContextAI

This vulnerability is classified as HTTP Request/Response Smuggling (CWE-444), which allows attackers to manipulate HTTP request interpretation between frontend and backend servers. 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.

Affected ProductsAI

See vendor advisory for affected versions.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Enforce strict HTTP parsing, normalize requests at proxy layer, use HTTP/2 end-to-end, reject ambiguous headers.