CVE-2026-23478: Cal Cal.com

Critical severity, CVSS 9.8. EPSS: 0.5% chance of exploitation in the next 30 days.

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

• Cal Cal.com: from 3.1.6, before 6.0.7 (fixed in 6.0.7)

Published 2026-01-13. Last modified 2026-06-17.