Cal Cal.Com vulnerabilities

CVE-2025-66489 [CRITICAL] CWE-303 CVE-2025-66489: Cal.com is open-source scheduling software. Prior to 5.9.8, A flaw in the login credentials provider Cal.com is open-source scheduling software. Prior to 5.9.8, A flaw in the login credentials provider allows an attacker to bypass password verification when a TOTP code is provided, potentially gaining unauthorized access to user accounts. This issue exists due to problematic conditional logic in the authentication flow. This vulnerability is fixe

CVE-2026-23478 [CRITICAL] CWE-602 CVE-2026-23478: Cal.com is open-source scheduling software. From 3.1.6 to before 6.0.7, there is a vulnerability in 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.

CVE-2023-1647 [HIGH] CWE-284 CVE-2023-1647: Improper Access Control in GitHub repository calcom/cal.com prior to 2.7. Improper Access Control in GitHub repository calcom/cal.com prior to 2.7.

CVE-2023-37919 [MEDIUM] CWE-613 CVE-2023-37919: Cal.com is open-source scheduling software. A vulnerability allows active sessions associated with a Cal.com is open-source scheduling software. A vulnerability allows active sessions associated with an account to remain active even after enabling 2FA. When activating 2FA on a Cal.com account that is logged in on two or more devices, the account stays logged in on the other device(s) stays logged in without having to verify the account owner's iden