How severe is GHSA-chx6-hx7r-mcp5?

No CVSS score has been assigned to GHSA-chx6-hx7r-mcp5 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-chx6-hx7r-mcp5?

GHSA-chx6-hx7r-mcp5 affects the following packages: react-router (npm). Ecosystems affected: npm.

How do I fix GHSA-chx6-hx7r-mcp5?

Update react-router to 7.18.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-chx6-hx7r-mcp5 is resolved across your whole dependency graph.

How do I detect GHSA-chx6-hx7r-mcp5 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for react-router, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-chx6-hx7r-mcp5 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is GHSA-chx6-hx7r-mcp5 actively exploited in the wild?

No public exploit code has been indexed for GHSA-chx6-hx7r-mcp5 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-chx6-hx7r-mcp5?

GHSA-chx6-hx7r-mcp5 has an EPSS (Exploit Prediction Scoring System) score of 0.7%, placing it in the 53th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-chx6-hx7r-mcp5?

GHSA-chx6-hx7r-mcp5 is classified as Uncontrolled Resource Consumption (CWE-400), CWE-407 (CWE-407). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-chx6-hx7r-mcp5 published, and has it been updated?

GHSA-chx6-hx7r-mcp5 was published on July 24, 2026 and was last updated on September 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

Not in CISA KEV

React Router: Unauthenticated Denial of Service via Inefficient Route MatchingGHSA-chx6-hx7r-mcp5

Fix: remix-run/react-router#15186

GHSA-chx6-hx7r-mcp5 is a Uncontrolled Resource Consumption vulnerability in react-router. A fix is available for react-router — see the affected versions and patch details below.

Also known asCVE-2026-55685

Published

Jul 24, 2026

Updated

Sep 10, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 22, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-chx6-hx7r-mcp5.

EPSS Exploitation Probability

via FIRST.org ↗

0.7%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs53th percentile — riskier than 53% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

9Kother npm packages depend on this — each one inherits the vulnerability until it's patched upstream

react-routernpm

35.6Mdownloads / week

Description

React Router is a router for React. In versions 7.0.0 through 7.17.0, the manifest endpoint could be accessed via unauthenticated targeted requests that would put heavy load on the server and slow down response times. This issue is a follow up to CVE-2026-42342, and does not does not impact React Router applications using Declarative Mode (<BrowserRouter>) or Data Mode (createBrowserRouter/<RouterProvider>). This issue has been fixed in version 7.18.0.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`react-router`	≥ 7.0.0&&< 7.18.0	7.18.0`npm install react-router@7.18.0`

Affected Products

1 product · 1 configurations

Application

react-routershopify

≥ 7.0.0 && < 7.18.0

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for react-router, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update react-router to 7.18.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-chx6-hx7r-mcp5 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

React Router (npm packages react-router and @remix-run/server-runtime) versions 7.0.0 through 7.17.0 expose an unauthenticated manifest endpoint. Repeated, targeted requests to this endpoint place heavy load on the server and can degrade or deny service for other users. This issue is a follow-up to CVE-2026-42342 and…

Workaround published by Red Hat

Upgrade to react-router/@remix-run/server-runtime 7.18.0 or later once the fix is packaged in the affected Red Hat product. Where upgrading isn't immediately possible, rate-limiting or restricting access to the manifest endpoint at a reverse proxy or ingress layer can reduce exposure. Products that do not run React Router in Framework Mode (Declarative Mode or Data Mode only) are not affected regardless of the bundled react-router version.

Source: Red Hat security advisory for GHSA-chx6-hx7r-mcp5 (CC BY 4.0)

Product	Fixed in	Advisory
Red Hat OpenShift AI 2.25	`rhoai/odh-dashboard-rhel9:1788312226`	RHSA-2026:65126
Red Hat OpenShift AI 3.4	`rhoai/odh-dashboard-rhel9:1787347991`	RHSA-2026:60520
Red Hat OpenShift AI 3.4	`rhoai/odh-mod-arch-eval-hub-rhel9:1791861214`	RHSA-2026:84734

Frequently Asked Questions

This is a follow up to https://github.com/remix-run/react-router/security/advisories/GHSA-8x6r-g9mw-2r78 that covers additional reported scenarios in which the manifest endpoint could be accessed via unauthenticated targeted requests that would put heavy load on the server and slow down response times. > [!NOTE] > This only impacts Framework Mode applications. This does not impact your application if you are using Declarative or Data Mode.

O3 Security · Impact-Aware SCA

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