# CVE-2026-9349: Cal.com cal.diy information disclosure in getServerSideProps

Source: https://junglewise.ai/threats/cve-2026-9349-cal-com-cal-diy-information-disclosure-in-getserversideprops  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-24. Updated: 2026-05-26  
License: CC BY 4.0 with a link back

CVE-2026-9349 · Severity: medium · CVSS 5.3 · Published 2026-05-24

Cal.com (cal.diy) is an open-source scheduling platform used to manage appointments and bookings. A privacy flaw allows unauthenticated users to see the private email addresses of event organizers, even when the 'hideOrganizerEmail' privacy setting is enabled. This occurs when an organizer cancels or reschedules a meeting, potentially exposing them to phishing or unwanted contact.

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

## Quick answers

**Is CVE-2026-9349 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-9349 being exploited in the wild.

**How severe is CVE-2026-9349?** Medium severity, with a CVSS score of 5.3, published 24 May 2026.

**Which products and versions are affected?** Cal.Com up to 4.9.4.

**Is there a fix for CVE-2026-9349?** No fixed version is recorded yet. Check the vendor's advisory in the references below. 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-2026-9349 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-9349?** Check whether you run Cal.Com 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.

## Technical details

An information exposure vulnerability exists in Cal.com (cal.diy) versions up to 4.9.4 within the 'getServerSideProps' function of the bookings module. The application fails to sanitize the 'cancelledBy' and 'rescheduledBy' properties in the bookingInfo JSON payload before it is serialized into the Server-Side Rendered (SSR) public page and TRPC API responses. An unauthenticated attacker with access to a public booking UID can retrieve the raw email address of the organizer if the organizer has performed a cancellation or rescheduling action. This bypasses the 'hideOrganizerEmail' security control intended to mask the organizer's identity. As of the advisory date, the vendor has not responded to the disclosure.

## Affected products

- Cal.com cal.diy up to 4.9.4

## Timeline

- 2026-04-06: disclosed: Vulnerability details and PoC shared via GitHub Gist
- 2026-05-24: advisory: CVE-2026-9349 published via VulDB/NVD

## References

- [https://gist.github.com/YLChen-007/b59c44d1550c4b0f373ca4eb1c150994](https://gist.github.com/YLChen-007/b59c44d1550c4b0f373ca4eb1c150994)
- [https://vuldb.com/submit/812177](https://vuldb.com/submit/812177)
- [https://vuldb.com/vuln/365312](https://vuldb.com/vuln/365312)
- [https://vuldb.com/vuln/365312/cti](https://vuldb.com/vuln/365312/cti)

## 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 remote code execution via Next.js RSC deserialization](https://junglewise.ai/threats/cve-2025-71389-cal-com-remote-code-execution-via-next-js-rsc-deserialization)
- [Cal.com stored XSS in booking question labels](https://junglewise.ai/threats/cve-2024-58355-cal-com-stored-xss-in-booking-question-labels)
- [Calcom cal.diy repository takeover via GitHub Actions pull_request_target](https://junglewise.ai/threats/cve-2024-58354-calcom-cal-diy-repository-takeover-via-github-actions-pull)