GHSA-g2r8-wvmj-jf5w
MEDIUMGHSA-g2r8-wvmj-jf5w is a medium-severity (CVSS 5.9) CWE-749 vulnerability in nx. O3 Security confirms whether GHSA-g2r8-wvmj-jf5w is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
`nx graph` dev server permissive CORS policy
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
nxnpmDescription
Summary
The local HTTP server started by nx graph sent Access-Control-Allow-Origin: * on every response, letting any website a developer visited read the server's responses cross-origin — including the full project graph and the output of the /help endpoint, which runs a target's configured help command. The practical impact is typically cross-origin information disclosure, but can be arbitrary command injection in rare cases.
Severity
Exploitation requires the developer to be running nx graph and to visit an attacker page. Any execution beyond benign help commands also requires a malicious target to already be present in the workspace (see Details).
Affected & Patched Versions
Package: nx (npm).
- Affected:
>= 17.0.4, < 22.7.2and>= 23.0.0-beta.0, < 23.0.0-beta.2 - Patched:
22.7.2+ (backport) and23.0.0(first in23.0.0-beta.2)
The wildcard CORS header was introduced in 17.0.4; the /help execution endpoint in 19.4.0. The 21.x line is not patched — 21.x users should upgrade to 22.7.2 or later.
Details
nx graph starts a local server (default http://127.0.0.1:4211). Before the fix, its request handler set a wildcard CORS header on every response:
res.setHeader('Access-Control-Allow-Origin', '*');
The /help endpoint runs a target's configured command:
const command = target.metadata?.help?.command;
return execSync(command, { cwd: target.options?.cwd ?? workspaceRoot }).toString();
A GET /help is a CORS "simple request", so a malicious page could fetch() it with no preflight, and the wildcard header let the page read the result. This exposes the project graph (project names, file paths, dependencies, build configuration) and the output of any configured help command.
The command is not attacker-controlled through the request — it comes from the workspace's project configuration, and first-party plugins (jest, vite, cypress) populate it with benign, read-only help commands. For /help to run anything malicious, a target carrying a malicious help.command must already exist in the project graph, which can only be introduced by installing a malicious package or by altering the workspace's own code/configuration — both of which already grant code execution independent of this flaw.
The fix (#35494) removes the header; the browser's same-origin policy then blocks cross-origin reads.
References
- Fix: nrwl/nx#35494
- Introduced: nrwl/nx#20744 (CORS), nrwl/nx#26629 (
/help)
Credits
Thanks to Nozomu Sasaki (Paul) (@morimori-dev) for finding and responsibly reporting this issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | nx | ≥ 17.0.4&&< 22.7.2 | 22.7.2 |
| 📦npm | nx | ≥ 23.0.0-beta.0&&< 23.0.0-beta.2 | 23.0.0-beta.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for nx. 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 nx to 22.7.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-g2r8-wvmj-jf5w 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-g2r8-wvmj-jf5w 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-g2r8-wvmj-jf5w. 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-g2r8-wvmj-jf5w in your dependencies?
O3 detects GHSA-g2r8-wvmj-jf5w across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.