# CVE-2026-104054: Cal.com cal.diy PBAC permission engine authorization bypass

Source: https://junglewise.ai/threats/cve-2026-104054-a-security-flaw-has-been-discovered-in-calcom-cal-diy-up-to-6-2  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-02. Updated: 2026-10-05  
License: CC BY 4.0 with a link back

CVE-2026-104054 · Severity: medium · CVSS 6.3 · Published 2026-10-02

Cal.com cal.diy is a scheduling and booking platform used to manage calendars and appointments. A flaw in the permission control system allows any authenticated user to access bookings and team events they should not have permission to view or modify, bypassing tenant isolation. This affects self-hosted instances where the permission engine is enabled by default.

Technologies: [Cal.com Cal.diy](https://junglewise.ai/threats/technologies/cal-diy). Vendors: [Cal.com](https://junglewise.ai/threats/vendors/cal-com).

## Quick answers

**Is CVE-2026-104054 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-104054 being exploited in the wild.

**How severe is CVE-2026-104054?** Medium severity, with a CVSS score of 6.3, published 2 October 2026.

**Which products and versions are affected?** Cal.com Cal.diy up to 6.2.0.

**Is there a fix for CVE-2026-104054?** No fixed version is recorded yet. Ensure the actual permission-check service implementation is imported and used in production code rather than the allow-all stub; add CI/CD guards to detect and prevent stub functions returning true for permission checks.</anigation>
</invoke> If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-104054 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-104054?** Check whether you run Cal.com Cal.diy at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix


Ensure the actual permission-check service implementation is imported and used in production code rather than the allow-all stub; add CI/CD guards to detect and prevent stub functions returning true for permission checks.</anigation>
</invoke>

## Technical details

The PBAC (Permission-Based Access Control) permission engine in the public codebase is shipped as non-functional stub implementations that always return true, particularly in PermissionCheckService.checkPermission(), hasPermission(), and the doesUserIdHaveAccessToBooking() function in BookingAccessService.ts. An authenticated attacker can call booking actions (confirm, reject, details, history) on team events they are not a member of, and the stub authorization check grants access. The real permission-check service exists only in test mocks and is never imported in production code.

## Affected products

- Cal.com cal.diy up to 6.2.0

## Timeline

- 2026-07-19: disclosed: Issue #29802 reported on GitHub
- 2026-10-02: advisory: CVE-2026-104054 published

## References

- [https://github.com/calcom/cal.diy/](https://github.com/calcom/cal.diy/)
- [https://github.com/calcom/cal.diy/issues/29802](https://github.com/calcom/cal.diy/issues/29802)

## Related threats

- [Cal.com authorization bypass in webhook handler](https://junglewise.ai/threats/cve-2026-112043-a-weakness-has-been-identified-in-calcom-cal-com-and-cal-diy-up)
- [Cal.com credentials delete cross-team privilege escalation](https://junglewise.ai/threats/cve-2026-109143-a-vulnerability-was-determined-in-calcom-cal-com-and-cal-diy-up)
- [Cal.com OSS authorization bypass in webhook creation](https://junglewise.ai/threats/cve-2026-16624-cal-com-oss-authorization-bypass-in-webhook-creation)