What’s Vulnerable › Vulnerabilities

CVE-2021-24927: My Calendar < 3.2.18 - Subscriber+ Reflected Cross-Site Scripting

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-11-29 · updated 2026-06-17
• Weakness: CWE-79

Description

The My Calendar WordPress plugin before 3.2.18 does not sanitise and escape the callback parameter of the mc_post_lookup AJAX action (available to any authenticated user) before outputting it back in the response, leading to a Reflected Cross-Site Scripting issue

Affected products

• Joseph C Dolson My Calendar: before 3.2.18 — fixed in 3.2.18

How to fix

Upgrade to a fixed version: Joseph C Dolson My Calendar 3.2.18. Check the vendor advisory for mitigations.

References

• https://wpscan.com/vulnerability/86f3acc7-8902-4215-bd75-6105d601524e
• https://wpscan.com/vulnerability/86f3acc7-8902-4215-bd75-6105d601524e

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