GHSA-mq3m-f8x3-579w
GHSA-mq3m-f8x3-579w is a Improper Authentication vulnerability in n8n. O3 Security confirms whether GHSA-mq3m-f8x3-579w is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
n8n: Cross-Issuer Token Exchange Account Binding via Subject-Only Identity Resolution
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
When an n8n instance is configured with more than one trusted token-exchange issuer, external identities are resolved to local accounts using only the JWT sub claim, ignoring the issuer (iss). As a result, two different issuers that emit the same subject value map to the same local account.
An attacker who can obtain a valid token from one trusted issuer with a sub matching a victim registered under a different issuer can authenticate as that victim and access their account.
This issue only affects instances where the token exchange feature is enabled and more than one trusted external issuer is configured.
Patches
The issue has been fixed in n8n version 2.28.1. 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:
- If multiple trusted issuers are not required, reduce the token exchange configuration to a single trusted issuer.
- Disable the token exchange feature entirely if it is not in active use.
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 | ≥ 2.28.0&&< 2.28.1 | 2.28.1 |
| 📦npm | n8n | all versions | 2.27.4 |
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 2.28.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-mq3m-f8x3-579w 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-mq3m-f8x3-579w 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-mq3m-f8x3-579w. 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-mq3m-f8x3-579w in your dependencies?
O3 detects GHSA-mq3m-f8x3-579w across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.