How severe is GHSA-h5cw-625j-3rxh?

GHSA-h5cw-625j-3rxh has a CVSS score of 6.5/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-h5cw-625j-3rxh?

GHSA-h5cw-625j-3rxh affects the following packages: react-router (npm), @remix-run/server-runtime (npm). Ecosystems affected: npm.

How do I fix GHSA-h5cw-625j-3rxh?

Update react-router to 7.12.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-h5cw-625j-3rxh is resolved across your whole dependency graph.

How do I detect GHSA-h5cw-625j-3rxh in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for react-router. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate GHSA-h5cw-625j-3rxh if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against GHSA-h5cw-625j-3rxh?

O3 pinpoints whether GHSA-h5cw-625j-3rxh is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-h5cw-625j-3rxh actively exploited in the wild?

No public exploit code has been indexed for GHSA-h5cw-625j-3rxh 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-h5cw-625j-3rxh?

GHSA-h5cw-625j-3rxh has an EPSS (Exploit Prediction Scoring System) score of 0.1%, placing it in the 3th 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-h5cw-625j-3rxh?

GHSA-h5cw-625j-3rxh is classified as CWE-346 (CWE-346), Cross-Site Request Forgery (CSRF) (CWE-352). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-h5cw-625j-3rxh published, and has it been updated?

GHSA-h5cw-625j-3rxh was published on January 8, 2026 and was last updated on June 9, 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

GHSA-h5cw-625j-3rxh

MEDIUM

React Router has CSRF issue in Action/Server Action Request Processing

Also known asCVE-2026-22030

Published

Jan 8, 2026

Updated

Jun 9, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.1%probability of exploitation in next 30 days

Lower Risk3th percentile+0.10%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

2 pkgs affected

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

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.

Description

React Router (or Remix v2) is vulnerable to CSRF attacks on document POST requests to UI routes when using server-side route action handlers in Framework Mode, or when using React Server Actions in the new unstable RSC modes.

[!NOTE] This does not impact your application if you are using Declarative Mode (<BrowserRouter>) or Data Mode (createBrowserRouter/<RouterProvider>).

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`react-router`	≥ 7.0.0&&< 7.12.0	7.12.0
📦npm	`@remix-run/server-runtime`	all versions	2.17.3

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. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update react-router to 7.12.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-h5cw-625j-3rxh is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-h5cw-625j-3rxh is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-h5cw-625j-3rxh. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

React Router (or Remix v2) is vulnerable to CSRF attacks on document POST requests to UI routes when using server-side route `action` handlers in [Framework Mode](https://reactrouter.com/start/modes#framework), or when using React Server Actions in the new unstable RSC modes. > [!NOTE] > This does not impact your application if you are using [Declarative Mode](https://reactrouter.com/start/modes#declarative) (`<BrowserRouter>`) or [Data Mode](https://reactrouter.com/start/modes#data) (`createBrowserRouter`/`<RouterProvider>`).

O3 Security · Impact-Aware SCA

Is GHSA-h5cw-625j-3rxh in your dependencies?

O3 detects GHSA-h5cw-625j-3rxh across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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