What is the CVSS score of CVE-2025-66489?

CVE-2025-66489 has a CVSS 3.1 base score of 9.8 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.1%.

Which versions of Cal.Com are affected by CVE-2025-66489?

Cal.com versions prior to the patched release contain a critical remote code execution vulnerability (CVSS 9.8) exploitable without authentication, enabling attackers to execute arbitrary code on…. A patch is available.

Is there a public PoC exploit available for CVE-2025-66489?

Yes, a public proof-of-concept exploit is available for CVE-2025-66489. Prioritise patching immediately. EPSS: 0.1%.

How to fix or mitigate CVE-2025-66489?

Within 24 hours: identify all Cal.com instances in production and document current versions. Within 7 days: apply the vendor-released security patch to all Cal.com deployments and verify successful installation. Within 30 days: conduct a post-incident review of access logs for the affected systems during the vulnerability window and implement enhanced monitoring for exploitation attempts.

Cal.Com CVE-2025-66489

EUVD-2025-201128 CRITICAL

Incorrect Implementation of Authentication Algorithm (CWE-303)

2025-12-03 security-advisories@github.com

Authentication Bypass Cal.Com

9.8

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

9.8 CRITICAL

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Updated

Apr 16, 2026 - 05:50 EUVD-patch-fix

executive_summary

Re-analysis Queued

Apr 16, 2026 - 05:29 backfill_euvd_patch

patch_released

Patch available

Apr 16, 2026 - 05:29 EUVD

5.9.8

EUVD ID Assigned

Mar 15, 2026 - 16:14 euvd

EUVD-2025-201128

Analysis Generated

Mar 15, 2026 - 16:14 vuln.today

PoC Detected

Feb 13, 2026 - 16:03 vuln.today

Public exploit code

CVE Published

Dec 03, 2025 - 20:16 nvd

CRITICAL 9.8

DescriptionGitHub Advisory

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.

AnalysisAI

A remote code execution vulnerability in Cal.com (CVSS 9.8) that allows an attacker. Risk factors: public PoC available.

Technical ContextAI

Vulnerability type: remote code execution. CVSS 9.8 indicates critical severity with likely remote exploitation vector. Affects Cal.com.

RemediationAI

Monitor vendor channels for patch availability.

CVE-2025-66489 vulnerability details – vuln.today

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Cal.Com CVE-2025-66489

Severity by source

CVSS VectorGitHub Advisory

Lifecycle Timeline

DescriptionGitHub Advisory

AnalysisAI

Technical ContextAI

RemediationAI

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External POC / Exploit Code