CVE-2021-24147: Modern Events Calendar Lite < 5.16.5 - Authenticated Stored Cross-Site Scripting (XSS)

Severity: medium (CVSS 5.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2021-03-18 · updated 2026-06-17
Weakness: CWE-79

Description

Unvalidated input and lack of output encoding in the Modern Events Calendar Lite WordPress plugin, versions before 5.16.5, did not sanitise the mic_comment field (Notes on time) when adding/editing an event, allowing users with privilege as low as author to add events with a Cross-Site Scripting payload in them, which will be triggered in the frontend when viewing the event.

Affected products

Modern Events Calendar Lite: before 5.16.5 — fixed in 5.16.5

How to fix

Upgrade to a fixed version: Modern Events Calendar Lite 5.16.5. Check the vendor advisory for mitigations.

References

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