CVE-2025-66489

Cal.com Authentication Bypass via bad TOTP + password checks

Published Dec 3, 2025 CVSS 4.0 · 9.9 Critical EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
CPEs cpe:2.3:a:cal:cal.com:*:*:*:*:*:*:*:*
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
First Time appeared Cal
Cal cal.com
Vendors & Products Cal
Cal cal.com
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title Cal.com Authentication Bypass via bad TOTP + password checks
Weaknesses CWE-303
References
Metrics cvssV4_0

{'score': 9.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Dec 3, 2025, 9:48 PM
Reserved
Dec 2, 2025, 10:44 PM
Status
Analyzed
Published
Dec 3, 2025, 8:16 PM
Modified
Oct 18, 2026, 6:10 PM