GHSA-83fc-fqcc-2hmg
HIGHReact Server Components have multiple Denial of Service Vulnerabilities
EPSS Exploitation Probability
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
react-server-dom-parcel📦react-server-dom-turbopack📦react-server-dom-webpack📦react-server-dom-turbopack📦react-server-dom-parcel📦react-server-dom-parcel📦react-server-dom-webpack📦react-server-dom-webpack+1 moreReal-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
Impact
It was found that the fixes to address DoS in React Server Components were incomplete and we found multiple denial of service vulnerabilities still exist in React Server Components.
We recommend updating immediately.
The vulnerability exists in versions 19.0.0, 19.0.1, 19.0.2, 19.0.3, 19.1.0, 19.1.1, 19.1.2, 19.1.3, 19.1.4, 19.2.0, 19.2.1, 19.2.2, 19.2.3 of:
The vulnerabilities are triggered by sending specially crafted HTTP requests to Server Function endpoints, and could lead to server crashes, out-of-memory exceptions or excessive CPU usage; depending on the vulnerable code path being exercised, the application configuration and application code.
Patches
Fixes were back ported to versions 19.0.4, 19.1.5, and 19.2.4.
If you are using any of the above packages please upgrade to any of the fixed versions immediately.
If your app’s React code does not use a server, your app is not affected by this vulnerability. If your app does not use a framework, bundler, or bundler plugin that supports React Server Components, your app is not affected by this vulnerability.
References
See the blog post for more information and upgrade instructions.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | react-server-dom-parcel | ≥ 19.0.0&&< 19.0.4 | 19.0.4 |
| 📦npm | react-server-dom-turbopack | ≥ 19.1.0-canary-7130d0c6-20241212&&< 19.1.5 | 19.1.5 |
| 📦npm | react-server-dom-webpack | ≥ 19.2.0-canary-63779030-20250328&&< 19.2.4 | 19.2.4 |
| 📦npm | react-server-dom-turbopack | ≥ 19.0.0&&< 19.0.4 | 19.0.4 |
| 📦npm | react-server-dom-parcel | ≥ 19.1.0-canary-7130d0c6-20241212&&< 19.1.5 | 19.1.5 |
| 📦npm | react-server-dom-parcel | ≥ 19.2.0-canary-63779030-20250328&&< 19.2.4 | 19.2.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for react-server-dom-parcel. 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-server-dom-parcel to 19.0.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-83fc-fqcc-2hmg 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-83fc-fqcc-2hmg 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-83fc-fqcc-2hmg. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-83fc-fqcc-2hmg in your dependencies?
O3 detects GHSA-83fc-fqcc-2hmg across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.