CVE-2025-66489— Cal.com Authentication Bypass via bad TOTP + password checks
Quick assessment
Affected
calcom cal.com
Exploitation
Public or AI PoC available; prioritize validation
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.
Cal.com是Cal.com开源的一个开源的日程安排软件。 Cal.com 5.9.8之前版本存在安全漏洞，该漏洞源于登录凭证提供程序存在逻辑缺陷，可能导致绕过密码验证和未授权访问。
Possible ATT&CK Techniques 1 AI
T1078 · Valid Accounts
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I. Basic Information for CVE-2025-66489
Vulnerability Information
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Vulnerability Title
Cal.com Authentication Bypass via bad TOTP + password checks
Source: CVE Program / CVE List V5
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.
Source: CVE Program / CVE List V5
CVSS Information
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
Source: CVE Program / CVE List V5
Vulnerability Type
认证算法的不正确实现
Source: CVE Program / CVE List V5
Vulnerability Title
Cal.com 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Cal.com是Cal.com开源的一个开源的日程安排软件。 Cal.com 5.9.8之前版本存在安全漏洞，该漏洞源于登录凭证提供程序存在逻辑缺陷，可能导致绕过密码验证和未授权访问。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)
Affected Products
II. Public POCs for CVE-2025-66489
| # | POC Description | Source Link | Shenlong Link |
|---|---|---|---|
| 1 | CVE-2025-66489 | https://github.com/Ashwesker/Blackash-CVE-2025-66489 | POC Details |
| 2 | CVE-2025-66489 | https://github.com/Ashwesker/Ashwesker-CVE-2025-66489 | POC Details |
AI-Generated POC
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IV. Related Vulnerabilities
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V. Comments for CVE-2025-66489
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