Review reviewHigh

CVE-2026-42342

remix-run react-router, @remix-run/server-runtime, remix-run/server-runtime

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 (`<BrowserRouter>`) or Data Mode (`createBrowserRouter/<RouterProvider>`). This is patched in...

CVSS: 7.5
EPSS: 0.30%
CISA KEV: Not listed
Published: 2026.06.03

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability0.30%

Technical severityCVSS 7.5

Vulnerability overview

Affected product and versions

Product: remix-run react-router, @remix-run/server-runtime, remix-run/server-runtime
Affected versions: >= >= 7.0.0, < 7.15.0, >= >= 2.10.0, < 2.17.5, >= 7.0.0 < 7.15.0, >= 2.10.0 < 2.17.5
Fixed versions: 7.15.0, 2.17.5

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that remix-run react-router, @remix-run/server-runtime, remix-run/server-runtime and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE: CWE-400