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ZITADEL: Missing Token Lifecyle Validation (`exp` and `iat`) in JWT IdP Provider

Moderate severity GitHub Reviewed Published Jun 17, 2026 in zitadel/zitadel • Updated Jul 18, 2026

Package

gomod github.com/zitadel/zitadel (Go)

Affected versions

< 1.80.0-v2.20.0.20260615122908-fad02c6d9f45

Patched versions

1.80.0-v2.20.0.20260615122908-fad02c6d9f45

Description

Summary

A token lifecycle validation vulnerability was discovered in ZITADEL's external JWT Identity Provider (IdP) implementation.
ZITADEL enforces a 1-hour maximum token age freshness window (maxAge) calculated from the token's issue time. However, this safety check is guarded by a presence condition. If an incoming token omits the iat claim, the freshness check is entirely bypassed, allowing arbitrarily old tokens to pass authentication successfully.

Per the OIDC Core 1.0 specification, identity token validation pipelines must strictly handle and enforce session expiration. ZITADEL's silent acceptance of tokens missing these temporal constraints compromises session integrity.

Impact

An attacker in possession of a stale token lacking an iat claim can reuse it indefinitely without triggering the maximum age freshness invalidation.

Affected Versions

Systems running one of the following versions are affected:

  • 4.x: 4.0.0 through 4.15.1 (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. ZITADEL now explicitly rejects tokens that lack an iat claim.

Workarounds

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

If an immediate upgrade is not feasible, ensure at the upstream Identity Provider level that your external IdP explicitly includes the iat claim in all signed JWTs.

Publication Note

This advisory covers a subset of the security issues originally published on ZITADEL's registry under this tracking ID. To adhere strictly to CVE formatting standards regarding independently fixable flaws, the original "Token Lifecycle Validation" disclosure has been split into two granular entries. This entry specifically tracks the missing iat claim logic, while a separate companion entry tracks the missing exp claim logic: GHSA-v77h-2w3m-94hx

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.

References

@livio-a livio-a published to zitadel/zitadel Jun 17, 2026
Published to the GitHub Advisory Database Jun 18, 2026
Reviewed Jun 18, 2026
Published by the National Vulnerability Database Jul 10, 2026
Last updated Jul 18, 2026

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
High
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(10th percentile)

Weaknesses

Insufficient Session Expiration

According to WASC, Insufficient Session Expiration is when a web site permits an attacker to reuse old session credentials or session IDs for authorization. Learn more on MITRE.

CVE ID

CVE-2026-56664

GHSA ID

GHSA-wxg7-w2v3-w38g

Source code

Credits

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