Cal develops a focused scheduling and calendar management platform, with its vulnerability footprint concentrated in the cal.com product. The recurring exposure pattern centers on authentication and access-control weaknesses, including authorization bypass through user-controlled keys, client-side security enforcement, improper access control, and insufficient session expiration, reflecting the session-management and permission-boundary demands inherent to multi-user scheduling applications. Current severity, exploitation activity, and exposure counts are shown alongside this summary.
The number and severity of CVEs published that impact products developed by Cal over time
Signals from CVEs in this vendor scope (4 CVEs).
4 CVEs · Highest risk first
| CVE | Published | CVSS | Risk | KEV | Exploit |
|---|---|---|---|---|---|
CVE-2026-23478CRITICAL 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 | Jan 13, 2026 | 9.8 | 35 | NO | NO |
CVE-2025-66489CRITICAL 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 | Dec 3, 2025 | 9.8 | 34 | NO | NO |
CVE-2023-1647HIGH Improper Access Control in GitHub repository calcom/cal.com prior to 2.7.
| Mar 27, 2023 | 8.8 | 28 | NO | NO |
CVE-2023-37919MEDIUM 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 | Jul 25, 2023 | 5.4 | 15 | NO | NO |
Signals from CVEs in this vendor scope (4 CVEs).
An overview of all social media posts that mention a CVE ID that affects a product developed by Cal.
Media articles that mention a CVE ID that affects a product developed by Cal — matched by CVE ID, not by vendor name.