CVE-2026-57858

CRITICAL CVSS 4.0: 9.3 EPSS 0.41%
Updated Aug 12, 2026
Cal.Com
Parameter Value
CVSS 9.3 (CRITICAL)
Affected Versions 2.1.1 — 6.2.0
Type CWE-79 (Cross-Site Scripting (XSS))
Vendor Cal.Com
Public PoC No

Cal.com Cal.diy versions 2.1.1 through 6.2.0 contain a stored cross-site scripting vulnerability in the BookingPageTagManager component that allows authenticated event owners to inject arbitrary JavaScript by supplying a malicious analytics tracking ID without sanitization. Attackers can close the inline script string literal with a crafted payload that executes in the browser of every visitor to the affected public booking page, enabling session cookie theft, forged authenticated requests, and wormable propagation by chaining with CSRF-able endpoints to persist payloads on additional events.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
Low
Basic privileges needed
User Interaction
Active
User action required

Impact Assessment

Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
Low
Partial disruption

CVSS Vector v4.0

Vulnerable Products

cal.com:cal.com self-hosted (cal.diy)