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CVE-2025-66489

Cal Cal.com vulnerability

9.8 CRITICALPublic exploitEPSS 0.84%
  1. Published3 Dec 2025

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 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

Cal Cal.com< 5.9.8

Remediation

Fixed in
Cal Cal.com≥ 5.9.8

References

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Frequently asked

Is CVE-2025-66489 being actively exploited?

CVE-2025-66489 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.84%.

How severe is CVE-2025-66489?

CVE-2025-66489 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.84% probability of exploitation.

Which products are affected by CVE-2025-66489?

Affected products include Cal Cal.com.

How do I fix CVE-2025-66489?

Upgrade affected software to a fixed version, for example Cal Cal.com 5.9.8 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2025-66489 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.