React Server Components have multiple Denial of Service VulnerabilitiesGHSA-83fc-fqcc-2hmg
HIGHGHSA-83fc-fqcc-2hmg is a high-severity (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in react-server-dom-parcel. A fix is available for react-server-dom-parcel — see the affected versions and patch details below.
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-83fc-fqcc-2hmg.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
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.
react-server-dom-parcelnpmreact-server-dom-turbopacknpmreact-server-dom-webpacknpmDescription
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 | 19.0.4npm install react-server-dom-parcel@19.0.4 |
| 📦npm | react-server-dom-turbopack | ≥ 19.1.0-canary-7130d0c6-20241212&&< 19.1.5 | 19.1.5npm install react-server-dom-turbopack@19.1.5 |
| 📦npm | react-server-dom-webpack | ≥ 19.2.0-canary-63779030-20250328&&< 19.2.4 | 19.2.4npm install react-server-dom-webpack@19.2.4 |
| 📦npm | react-server-dom-turbopack | ≥ 19.0.0&&< 19.0.4 | 19.0.4npm install react-server-dom-turbopack@19.0.4 |
| 📦npm | react-server-dom-parcel | ≥ 19.1.0-canary-7130d0c6-20241212&&< 19.1.5 | 19.1.5npm install react-server-dom-parcel@19.1.5 |
| 📦npm | react-server-dom-parcel | ≥ 19.2.0-canary-63779030-20250328&&< 19.2.4 | 19.2.4npm install react-server-dom-parcel@19.2.4 |
Affected Products
reactfacebookDetection & 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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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
Do not deserialise data from untrusted sources: where the format allows it, restrict deserialisation to an explicit allowlist of expected types, and prefer a data-only format (JSON, Protobuf) over one that can reconstruct arbitrary objects until you can upgrade.
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.
| Product | Fixed in | Advisory |
|---|---|---|
| Streams for Apache Kafka 2.9.4 | com.github.streamshub-console | RHSA-2026:34608 |
| Streams for Apache Kafka 3.2.0 | com.github.streamshub-console | RHSA-2026:13571 |
Frequently Asked Questions
Is GHSA-83fc-fqcc-2hmg in your dependencies?
Find it across npm, including transitive dependencies.