CVE-2026-40308

Published: Apr 17, 2026 Last Modified: Apr 17, 2026
ExploitDB:
Other exploit source:
Google Dorks:
HIGH 8,8
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Confidentiality: N/A
Integrity: N/A
Availability: N/A

Description

AI Translation Available

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.

639

Authorization Bypass Through User-Controlled Key

Incomplete
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Access Control
Potential Impacts:
Bypass Protection Mechanism Gain Privileges Or Assume Identity
Applicable Platforms
All platforms may be affected
Likelihood of Exploit: High
View CWE Details
https://github.com/joedolson/my-calendar/releases/tag/v3.7.7
https://github.com/joedolson/my-calendar/releases/tag/v3.7.7
https://github.com/joedolson/my-calendar/security/advisorie…
https://github.com/joedolson/my-calendar/security/advisories/GHSA-2mvx-f5qm-v2ch