Is there a public exploit for CVE-2026-42342?

No public exploit for CVE-2026-42342 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2026-42342?

CVE-2026-42342 scores CVSS 7.5 (v3.1), rated high. EPSS puts the chance of exploitation in the next 30 days at 0.3%.

What does CVE-2026-42342 affect?

CVE-2026-42342 affects remix-run react-router, @remix-run/server-runtime.

7.5 High

React Router is a router for React.

CVE-2026-42342

React Router is a router for React. In versions 7.0.0 through 7.14.x of react-router and versions 2.10.0 through 2.17.4 of @remix-run/server-runtime, certain crafted requests can consume disproportionate server resources via unbounded path expansion in the manifest endpoint, resulting in response time degradation and/or service unavailability for end users. This affects React Router Framework Mode applications as well as Remix applications. This does not impact applications using Declarative Mode ( ) or Data Mode (createBrowserRouter/ ). This is patched in react-router version 7.15.0 and @remix-run/server-runtime version 2.17.5.

Assessment

CVSS: 7.5 (v3.1)
Severity: High
EPSS: 0.3% chance of exploitation in the next 30 days
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 2 June 2026
Last updated: 21 July 2026
Affected: remix-run · @remix-run/server-runtime · react-router · react-router · @remix-run/server-runtime
Weakness: CWE-400
Assigner: security-advisories@github.com

CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

At the source

References

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