CVE-2026-56665: ZITADEL: Missing Token Expiration (`exp`) Validation in JWT IdP Provider

A token lifecycle validation vulnerability was discovered in ZITADEL’s external JWT Identity Provider (IdP) implementation Specifically, within the validation pipeline, if an incoming JWT omits the exp claim entirely, the expiration block is silently skipped rather than rejected. The token is treated as valid forever.

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.