GHSA-g5h5-m4hm-xjrr

Suggest an improvement
Source
https://github.com/advisories/GHSA-g5h5-m4hm-xjrr
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-g5h5-m4hm-xjrr/GHSA-g5h5-m4hm-xjrr.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-g5h5-m4hm-xjrr
Aliases
  • CVE-2026-55669
Published
2026-06-18T13:52:24Z
Modified
2026-06-18T14:00:10.148199277Z
Severity
  • 4.2 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N CVSS Calculator
Summary
ZITADEL: Missing Token Audience Validation (`aud`) in JWT IdP Provider
Details

Summary

An authentication bypass vulnerability was discovered in ZITADEL's external JWT Identity Provider (IdP) implementation.

When validating JSON Web Tokens (JWTs) from an external provider, ZITADEL properly checks the token's cryptographic signature and issuer (iss), but it fails to validate the audience (aud) claim.

As a result, any validly signed token from the trusted issuer will be accepted. An attacker who is a legitimate user of a completely separate service sharing the same enterprise Identity Provider can intercept or present their token for that service to ZITADEL, successfully authenticating as that user without authorization.

Impact

In a controlled enterprise environment where Identity Providers are explicitly managed, the operational risk is localized. Exploitation requires that an attacker already possesses a valid standard user session token from a shared, trusted issuer intended for an entirely different relying party, limiting the vector to specific, rare cross-service setups where trust boundaries overlap.

Affected Versions

Systems running one of the following versions are affected:

  • 4.x: 4.0.0 through 4.11.0 (including RC versions)
  • 3.x: 3.0.0 through 3.4.11 (including RC versions)

Patches

The vulnerability has been addressed in the latest releases, where a required audience can be set in the IdP configuration. Once provided, audience validation will be enforced.

Workarounds

The recommended solution is to update ZITADEL to a patched version.

If an immediate upgrade is not possible, you can mitigate the risk at the infrastructure layer:

  1. At the IdP: Ensure the external Identity Provider issues scoped tokens with highly unique, non-overlapping audience values that cannot be misconstrued by separate service deployments.
  2. At the Perimeter: Deploy a reverse proxy, API gateway, or Web Application Firewall (WAF) layer in front of ZITADEL to inspect incoming identity tokens and explicitly drop requests where the aud field does not strictly match ZITADEL's deployment target.

Questions

If you have any questions or comments about this advisory, please email us at security@zitadel.com

Credits

Thanks to Android-Login-Analysis, Jason Zhou and Pedro Giglioti for reporting this vulnerability.

Database specific 
{
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-18T13:52:24Z",
    "nvd_published_at": null,
    "severity": "MODERATE",
    "cwe_ids": [
        "CWE-346"
    ]
}
References

Affected packages

Go / github.com/zitadel/zitadel

Package

Name
github.com/zitadel/zitadel
View open source insights on deps.dev
Purl
pkg:golang/github.com/zitadel/zitadel

Affected ranges

Type
SEMVER
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
1.80.0-v2.20.0.20260615132747-d184e976fc79

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-g5h5-m4hm-xjrr/GHSA-g5h5-m4hm-xjrr.json"