GHSA-537j-gqpc-p7fq
HIGHGHSA-537j-gqpc-p7fq is a high-severity (CVSS 8.2) Cross-site Scripting (XSS) vulnerability in n8n. O3 Security confirms whether GHSA-537j-gqpc-p7fq is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
n8n Vulnerable to XSS via MCP OAuth client
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
n8nnpmDescription
Impact
An unauthenticated attacker could register a malicious MCP OAuth client with a crafted client_name. If a victim user authorized the OAuth consent dialog and a second user subsequently revoked that access, a toast notification would render the injected script. Clicking the link would execute arbitrary JavaScript in the victim's authenticated n8n browser session, enabling credential and session token theft, workflow manipulation, or privilege escalation.
Patches
This issue has been fixed in n8n version 2.14.2. Users should upgrade to this version or later to remediate the vulnerability.
Workarounds
If upgrading is not immediately possible, administrators should consider the following temporary mitigations:
- Restrict access to the n8n instance and the MCP OAuth registration endpoint to trusted users only.
- Disable MCP server functionality if it is not actively required.
These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | n8n | all versions | 1.123.32 |
| 📦npm | n8n | ≥ 2.18.0&&< 2.18.1 | 2.18.1 |
| 📦npm | n8n | ≥ 2.17.0&&< 2.17.4 | 2.17.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for n8n. 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 n8n to 1.123.32 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-537j-gqpc-p7fq 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-537j-gqpc-p7fq 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-537j-gqpc-p7fq. 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-537j-gqpc-p7fq in your dependencies?
O3 detects GHSA-537j-gqpc-p7fq across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.