CVE-2021-24943: Registrations for the Events Calendar < 2.7.6 - Unauthenticated SQL Injection

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 7.3% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2021-12-06 · updated 2026-06-17
Weakness: CWE-89

Description

The Registrations for the Events Calendar WordPress plugin before 2.7.6 does not sanitise and escape the event_id in the rtec_send_unregister_link AJAX action (available to both unauthenticated and authenticated users) before using it in a SQL statement, leading to an unauthenticated SQL injection.

Affected products

Registrations for the Events Calendar – Event Registration Plugin: before 2.7.6 — fixed in 2.7.6

How to fix

Upgrade to a fixed version: Registrations for the Events Calendar – Event Registration Plugin 2.7.6. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2021-24943 or the next vulnerability affects your stack