vulnerability / NVI-00016101 / Revision 1
n8n: Cross-Issuer Token Exchange Account Binding via Subject-Only Identity Resolution
GitHub lists this reviewed advisory for n8n, n8n. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
n8n
source listed>= 2.28.0, < 2.28.1
## 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.
n8n
source listed< 2.27.4
## 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.
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-mq3m-f8x3-579w ↗
GitHub Advisory Database · vendor advisory
Observed . GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.