CVE-2026-57858

critical

Description

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.

References

https://www.vulncheck.com/advisories/cal-com-cal-diy-stored-xss-via-bookingpagetagmanager-analytics-tracking-id

https://github.com/calcom/cal.com

https://ashtonr.com/blog/cve-2026-57858/

Details

Source: Mitre, NVD

Published: 2026-08-12

Updated: 2026-08-12

Risk Information

CVSS v2

Base Score: 8.7

Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:C/A:P

Severity: High

CVSS v3

Base Score: 8.9

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

Severity: High

CVSS v4

Base Score: 9.3

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L

Severity: Critical