← Vulnerability feed

Vulnerability record · CVE-2025-66489 · published 3 December 2025

CVE-2025-66489: Cal.com vulnerability

Cal · Cal.Com

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.

9.9 CVSS 4.0 Critical EPSS 0.84% · top 43.8% CWE-303 · CWE-303
9.9CVSS 4.0 base score
0.84%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
1References, 1 tagged exploit
17 Jun 2026Last modified by NVD

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.

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/calcom/cal.com/security/advisories/GHSA-9r3w-4j8q-pw98 ExploitThird Party Advisory

Track CVE-2025-66489 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

10.0CVE-2026-23478Cal.com insecure direct object reference vulnerabilityCal.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 attack…EPSS 0.46%8.8CVE-2023-1647Cal.com improper access control vulnerabilityImproper Access Control in GitHub repository calcom/cal.com prior to 2.7.EPSS 0.84%5.4CVE-2023-37919Cal.com insufficient session expiration vulnerabilityCal.com is open-source scheduling software. A vulnerability allows active sessions associated with an account to remain active even after enabling 2F…EPSS 0.31%9.8CVE-2024-7593Ivanti vTM authentication bypass in admin panelIvanti Virtual Traffic Manager (vTM) versions other than 22.2R1 or 22.7R2 implement an authentication algorithm incorrectly, allowing an attacker to …KEVEPSS 100%analysed9.8CVE-2023-29357Microsoft SharePoint Server elevation of privilege via authentication bypassCVE-2023-29357 is a critical elevation of privilege flaw in Microsoft SharePoint Server. The CVSS vector shows it is network reachable with no privil…KEVEPSS 100%analysed

Source: NIST National Vulnerability Database (record CVE-2025-66489), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.