CVE-2026-77129: Server-Side Template Injection in extension "Event management and registration" (sf_event_mgt)

Vulnerability summary

CVE-2026-77129 is a high (CVSS 7.7) vulnerability in typo3 extension "event management and registration". EPSS estimates a 0.40% chance of exploitation in the next 30 days, higher than 33.8% of scored vulnerabilities.

Timeline

1. 25-08-2026
   PublishedVulnerability first disclosed.
2. 25-08-2026
   Last modifiedVulnerability information updated.

Description

The extension passes an editor-configurable email subject string directly into a Fluid template source without restriction. A backend user with edit access to the event plugin or Backend Module can supply Fluid ViewHelper syntax in this field to disclose sensitive data or execute TypoScript content objects. Exploitation of this issue requires an authenticated backend account with edit access to the event registration plugin or backend module.

• CWE-1336Improper Neutralization of Special Elements Used in a Template EngineThe product uses a template engine to insert or process externally-influenced input, but it does not neutralize or incorrectly neutralizes special elements or syntax that can be interpreted as template expressions or other code directives when processed by the engine.