CVE-2025-66489 - CVE House
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Status published Critical CVE-2025-66489

Cal.com Authentication Bypass via bad TOTP + password checks

Vulnerability Description

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 fixed in 5.9.8.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

No credits recorded in the NVD database.

References

More from calcom

View All →
CVE-2023-37919
Cal.com not expiring old sessions after enabling 2FA
Medium 6.5
CVE-2023-1647
Improper Access Control in calcom/cal.com
High 8.8

Affected Vendor

Affected Software

cal.com
Vulnerable Versions:
< 5.9.8

Timeline

Official Publish: December 3rd, 2025
Last Modified: December 3rd, 2025
Added to House: July 22nd, 2026

CVSS Vectors

Weaknesses (CWE)

CWE-303

MITRE ATT&CK TTPs

No associated TTPs found for this vulnerability.