Is CVE-2026-91109 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-91109 being exploited in the wild.

How severe is CVE-2026-91109?

Medium severity, with a CVSS score of 6.5, published 1 October 2026.

Which products and versions are affected?

Simply Schedule Appointments up to 1.6.12.31.

Is there a fix for CVE-2026-91109?

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-2026-91109 attacked?

It is attacked over the network, in a web application.

Am I affected by CVE-2026-91109?

Check whether you run Simply Schedule Appointments 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.

CVE-2026-91109: Simply Schedule Appointments insecure direct object reference

CVE-2026-91109 · Severity: medium · CVSS 6.5 · Published 2026-10-01

The Simply Schedule Appointments WordPress plugin allows authenticated users to expose private appointment tokens and personal information of other appointment participants. An attacker with subscriber access can leak co-bookers' identity tokens and contact details, then use those tokens to read, modify, or cancel other users' appointments, compromising privacy and availability of scheduling data.

Technologies: Simply Schedule Appointments. Vendors: Simply Schedule Appointments.

Quick answers

Is CVE-2026-91109 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-91109 being exploited in the wild.
How severe is CVE-2026-91109?: Medium severity, with a CVSS score of 6.5, published 1 October 2026.
Which products and versions are affected?: Simply Schedule Appointments up to 1.6.12.31.
Is there a fix for CVE-2026-91109?: 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-2026-91109 attacked?: It is attacked over the network, in a web application.
Am I affected by CVE-2026-91109?: Check whether you run Simply Schedule Appointments 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 Insecure Direct Object Reference (IDOR) vulnerability in the 'complete_group' parameter allows authenticated attackers to bypass access controls on appointment data. The REST controller fails to validate user-controlled keys, enabling disclosure of per-appointment id_token values (as public_token) and PII, and subsequent manipulation of appointment metadata. Exploitation requires a valid id_token for one appointment in the targeted group.

Affected products

Simply Schedule Appointments Simply Schedule Appointments up to 1.6.12.31

Timeline

2026-10-01: disclosed

References

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