Cross-tenant booking disclosure via unchecked webhook teamId
Published Jul 22, 2026 · Updated Jul 22, 2026
Authorization bypass in Cal.com Cal.diy before 6.2.0 allows remote authenticated users to exfiltrate team booking data through webhooks. The webhook creation handler writes an attacker-supplied teamId into a new row without checking the caller's membership, so normal delivery sends that team's events to the chosen subscriber URL. Any authenticated account and a target team's numeric identifier are sufficient; exposed payloads include attendee and organizer details, custom responses, and, when present, video-call credentials.
Summary
What happened
Authorization bypass in Cal.com Cal.diy before 6.2.0 allows remote authenticated users to exfiltrate team booking data through webhooks. The webhook creation handler writes an attacker-supplied teamId into a new row without checking the caller's membership, so normal delivery sends that team's events to the chosen subscriber URL. Any authenticated account and a target team's numeric identifier are sufficient; exposed payloads include attendee and organizer details, custom responses, and, when present, video-call credentials.
The record
- CVE
- CVE-2026-16624
- Published
- Jul 22, 2026
- Updated
- Jul 22, 2026
- Vendor
- Cal.com, Inc.
- Product
- Cal.diy
- Classifications
- CWE-639, T1567.004
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 22, 2026CVE publishedPublication date reported by the CVE source.
- Jul 22, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <6.2.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Cross-tenant webhook planting requestfunctional · demonstrated
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Technologies
Your stack
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Your stack
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