CVE-2026-40308

My Calendar is a WordPress plugin for managing calendar events. In versions 3.7.6 and below, the mc_ajax_mcjs_action AJAX endpoint, registered for unauthenticated users, passes user-supplied arguments through parse_str() without validation, allowing injection of arbitrary parameters including a site value. On WordPress Multisite installations, this enables an unauthenticated attacker to call switch_to_blog() with an arbitrary site ID and extract calendar events from any sub-site on the network, including private or hidden events. On standard Single Site installations, switch_to_blog() does not exist, causing an uncaught PHP fatal error and crashing the worker thread, creating an unauthenticated denial of service vector. This issue has been fixed in version 3.7.7.

CVSS

No CVSS.

References

Link	Resource
https://github.com/joedolson/my-calendar/releases/tag/v3.7.7
https://github.com/joedolson/my-calendar/security/advisories/GHSA-2mvx-f5qm-v2ch
https://github.com/joedolson/my-calendar/security/advisories/GHSA-2mvx-f5qm-v2ch

Configurations

No configuration.

History

17 Apr 2026, 13:16

Type	Values Removed	Values Added
References	~~() https://github.com/joedolson/my-calendar/security/advisories/GHSA-2mvx-f5qm-v2ch -~~	() https://github.com/joedolson/my-calendar/security/advisories/GHSA-2mvx-f5qm-v2ch -

16 Apr 2026, 22:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-04-16 22:16

Updated : 2026-04-17 15:38

NVD link : CVE-2026-40308

Mitre link : CVE-2026-40308

CVE.ORG link : CVE-2026-40308

JSON object : View

Products Affected

No product.

CWE

CWE-639

Authorization Bypass Through User-Controlled Key

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