PoC Index

CVE-2026-57858

CRITICAL 9.3EPSS 0.4%

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.

CVSS v4.0
9.3 CRITICALCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L/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:X/V:X/RE:X/U:X
CVSS v3.1
8.9 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L
EPSS
0.37% chance of exploitation in the next 30 days, 30th percentile
Published
2026-08-12
Updated
2026-08-13

Proof-of-concept exploits (1)

References

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