Paper/Archive/CVE-2026-57858

CVE-2026-57858

Cal.com Cal.com Self-Hosted (Cal.diy) — Cal.com Cal.diy 6.2.0 Stored XSS via BookingPageTagManager Analytics Tracking ID

EPSS 0.4%public exploit CVSS 9.3

critical.is priorityof 100

CVSS 9.3 (CNA)9.3 / 10 × 3027.9 Not in CISA KEV+300.0 EPSS percentile 30.9.309 × 206.2 Exploit: SSVC poc+1010.0 SSVC exploitation: poc+100.0

Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource

Cal.com Self-Hosted (Cal.diy)2.1.1 – 6.2.0–CNA

Scores by source

VulnCheck (CNA)9.3CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L

VulnCheck (CNA)8.9CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L

CISA ADPSSVCExploitation: poc · Automatable: no · Technical impact: total

References

refgithub.com/calcom/cal.com exploitashtonr.com/blog/cve-2026-57858 writeupvulncheck.com/advisories/cal-com-cal-diy-stored-xss-via-bookingpagetagmanager-analytics-tracking-id