ZITADEL: Missing Token Audience Validation (aud) in JWT IdP Provider

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

4.2 · CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N

EPSS

• CVE-2026-55669: 0.15% estimated exploitation activity in the next 30 days; percentile 4.66 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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…

Published by the source

18 Jun 2026, 13:52 UTC

Last modified by the source

18 Jun 2026, 13:52 UTC

Source last checked

26 Oct 2026, 15:24 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-g5h5-m4hm-xjrr

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# Patch Next advisory brief: CVE-2026-55669

Advisory: ZITADEL: Missing Token Audience Validation (`aud`) in JWT IdP Provider
IDs: CVE-2026-55669, GHSA-g5h5-m4hm-xjrr
Record: https://patchnext.com/advisories/cve-2026-55669 (revision 1, source checked 26 Oct 2026, 15:24 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.2)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/zitadel/zitadel 1.80.0-v2.20.0.20260615132747-d184e976fc79. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/zitadel/zitadel: affected < 1.80.0-v2.20.0.20260615132747-d184e976fc79; fixed in 1.80.0-v2.20.0.20260615132747-d184e976fc79

## Suggested inspection (read-only)
- Go github.com/zitadel/zitadel: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/zitadel/zitadel.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-g5h5-m4hm-xjrr (GitHub-reviewed advisory GHSA-g5h5-m4hm-xjrr lists affected ranges: Go github.com/zitadel/zitadel >=0 <1.80.0-v2.20.0.20260615132747-d184e976fc79)

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