GHSA-hfmv-hhh3-43f2 is a high-severity (CVSS 8.7) Cross-site Scripting (XSS) vulnerability in n8n. O3 Security confirms whether GHSA-hfmv-hhh3-43f2 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Stored XSS in n8n Form Trigger allows Account Takeover via injected iframe and video/source
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, a proxy for how much of the ecosystem is exposed.
n8nnpmDescription
Impact
A stored Cross-Site Scripting (XSS) vulnerability was identified in n8n, specifically in the Form Trigger node's HTML form element. An authenticated attacker can inject malicious HTML via an <iframe> with a srcdoc payload that includes arbitrary JavaScript execution. The attacker can also inject malicious Javascript by using <video> coupled <source> using an onerror event.
While using iframe or a combination of video and source tag, this vulnerability allows for Account Takeover (ATO) by exfiltrating n8n-browserId and session cookies from authenticated users who visit a maliciously crafted form. Using these tokens and cookies, an attacker can impersonate the victim and change account details such as email addresses, enabling full control over the account—especially if 2FA is not enabled.
Patches
The issue was addressed in PR #16329. Users should upgrade to version >=1.98.2.
Workarounds
Apart from updating to the fixed version, n8n instance administrators can:
- Configure a reverse proxy to serve webhook requests from a different domain [docs].
- Disable or restrict use of the Form Trigger node, particularly the HTML element type.
- Use a Content Security Policy (CSP) to block execution of inline scripts and disallow use of
srcdoc.
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | n8n | ≥ 1.77.0&&< 1.98.2 | 1.98.2 |
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 1.98.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-hfmv-hhh3-43f2 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-hfmv-hhh3-43f2 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-hfmv-hhh3-43f2. 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-hfmv-hhh3-43f2 in your dependencies?
O3 detects GHSA-hfmv-hhh3-43f2 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.