CVE-2026-42342

React Router vulnerable to DoS via unbounded path expansion in __manifest endpoint

HIGH
7.5
CVSS Score
Published: June 2, 2026 at 06:23 PM UTC
Updated: July 21, 2026 at 07:26 PM UTC
4 products affected across 2 vendorsReact RouterRemix Run /server RuntimeReact Router

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Severity
HIGH7.5
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

Description

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 react-router version 7.15.0 and @remix-run/server-runtime version 2.17.5.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

7.0.0 ≤ v < 7.15.0
Affected range stops below 7.15.0, so it looks safe — our inference, not a vendor statement
2.10.0 ≤ v < 2.17.5
Affected range stops below 2.17.5, so it looks safe — our inference, not a vendor statement
v < 7.15.0
Affected range stops below 7.15.0, so it looks safe — our inference, not a vendor statement
v < 2.17.5
Affected range stops below 2.17.5, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (1)

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-400

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