CVE-2026-16624: CVE-2026-16624

Severity: critical (CVSS 9.6 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-22 · updated 2026-10-24
Weakness: CWE-639

Description

Cal.com OSS ships lacks authorization on webhook teamId creation, allowing any authenticated user to create a webhook on any team via unvalidated teamId injection, then steal booking data, including fields like organizer/attendee emails and custom responses, and conditionally video-call passwords, by triggering webhook delivery.

Affected products

Cal.com Cal.diy: before 6.2.0 — fixed in 6.2.0

How to fix

Upgrade to a fixed version: Cal.com Cal.diy 6.2.0. Check the vendor advisory for mitigations.

References

https://github.com/calcom/cal.diy/security/advisories/GHSA-4fwh-xxpv-xfm6
https://vokecyber.com/research/calcom-cross-tenant-webhook-plant
https://vokecyber.com/research/calcom-cross-tenant-webhook-plant

Get alerted when CVE-2026-16624 or the next vulnerability affects your stack