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OpenAdvisories
Critical · 10.0 CVE-2026-23478 EUVD-2026-2413

Cal.com has an Authentication Bypass via Unvalidated Email in Custom JWT Callback

Published Jan 13, 2026 · Updated Jan 14, 2026 · Assigned by GitHub_M

Description

Cal.com is open-source scheduling software. From 3.1.6 to before 6.0.7, there is a vulnerability in a custom NextAuth JWT callback that allows attackers to gain full authenticated access to any user's account by supplying a target email address via session.update(). This vulnerability is fixed in 6.0.7.

Affected products

VendorProductAffectedFixed
calcom cal.com >= 3.1.6, < 6.0.7 —

References