GHSA-479c-33wc-g2pg
HIGHGHSA-479c-33wc-g2pg is a high-severity (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in react-server-dom-parcel. O3 Security confirms whether GHSA-479c-33wc-g2pg is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
React Server Components have a Denial of Service Vulnerability
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
react-server-dom-parcelnpmDescription
Impact
A denial of service vulnerability exists in React Server Components, affecting the following packages: react-server-dom-parcel, react-server-dom-turbopack, react-server-dom-webpack versions 19.0.0, 19.1.0 and 19.2.0. The vulnerability is triggered by sending specially crafted HTTP requests to Server Function endpoints.
The payload of the HTTP request causes excessive CPU usage for up to a minute ending in a thrown error that is catchable.
We recommend updating immediately.
The vulnerability exists in versions 19.0.0 through 19.0.4, 19.1.0 through 19.1.5, and 19.2.0 through 19.2.4 of:
react-server-dom-webpack react-server-dom-parcel react-server-dom-turbopack
Patches
Fixes were back ported to versions 19.0.5, 19.1.6, and 19.2.5.
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&&< 19.0.5 | 19.0.5 |
| 📦npm | react-server-dom-parcel | ≥ 19.1.0&&< 19.1.6 | 19.1.6 |
| 📦npm | react-server-dom-parcel | ≥ 19.2.0&&< 19.2.5 | 19.2.5 |
| 📦npm | react-server-dom-turbopack | ≥ 19.0.0&&< 19.0.5 | 19.0.5 |
| 📦npm | react-server-dom-turbopack | ≥ 19.1.0&&< 19.1.6 | 19.1.6 |
| 📦npm | react-server-dom-turbopack | ≥ 19.2.0&&< 19.2.5 | 19.2.5 |
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 19.0.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-479c-33wc-g2pg 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-479c-33wc-g2pg 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-479c-33wc-g2pg. 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-479c-33wc-g2pg in your dependencies?
O3 detects GHSA-479c-33wc-g2pg across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.