CVE-2026-16624: Cal.com OSS ships lacks authorization on webhook teamId creation, allowing any authenticated user to create a

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CRITICAL 9.6

CVE-2026-16624 is a critical-severity flaw (CVSS 9.6) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

Critical severity
CISA SSVC: public proof of concept

A fixed release or distro patch exists.

Risk facts

CVSS score	9.6 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.4% (top 67%)
CISA exploited list	No
Weakness	CWE-639
Published	2026-07-22
Last modified	2026-10-24

Publisher (CNA): CERT/CC

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Timeline

2026-07-22 19:16 UTCPublished CVE record published
2026-10-24 13:10 UTCUpdated Record last modified

Exact fixes by distribution

Fedora 46 · gnome-shell-extension-tiling-assistant · FIXED · 56-1.fc46 · FEDORA-2026-ebf66a5321 · source

sudo dnf upgrade --advisory=FEDORA-2026-ebf66a5321

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Write-up: vokecyber.com/research/calcom-cross-tenant-webhook-plant

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-16624?

No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.

Is CVE-2026-16624 being exploited?

CVE-2026-16624 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-16624 affect?

CVE-2026-16624 affects affected software. Severity is critical (CVSS 9.6). 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

How urgent is CVE-2026-16624?

Priority 45/100. Critical severity; CISA SSVC: public proof of concept

References

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