GHSA-6x33-pw7p-hmpq is a high-severity (CVSS 7.5) vulnerability in http-proxy. O3 Security confirms whether GHSA-6x33-pw7p-hmpq is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Denial of Service in http-proxy
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.
http-proxynpmDescription
Versions of http-proxy prior to 1.18.1 are vulnerable to Denial of Service. An HTTP request with a long body triggers an ERR_HTTP_HEADERS_SENT unhandled exception that crashes the proxy server. This is only possible when the proxy server sets headers in the proxy request using the proxyReq.setHeader function.
For a proxy server running on http://localhost:3000, the following curl request triggers the unhandled exception:
curl -XPOST http://localhost:3000 -d "$(python -c 'print("x"*1025)')"
Recommendation
Upgrade to version 1.18.1 or later
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | http-proxy | all versions | 1.18.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for http-proxy. 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 http-proxy to 1.18.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-6x33-pw7p-hmpq 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-6x33-pw7p-hmpq 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-6x33-pw7p-hmpq. 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-6x33-pw7p-hmpq in your dependencies?
O3 detects GHSA-6x33-pw7p-hmpq across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.