CVE-2026-77129: CWE-1336 Improper Neutralization of Special Elements Used in a Template Engine in TYPO3 Extension "Event management and registration"
Description
CVE-2026-77129 is a high-severity vulnerability in the TYPO3 extension "Event management and registration." It allows a backend user with edit access to supply malicious Fluid ViewHelper syntax in an email subject field, which is passed directly into a Fluid template without restriction. This can lead to disclosure of sensitive data or execution of TypoScript content objects. Exploitation requires authenticated backend access with edit permissions to the event plugin or backend module.
CVSS v4.0
Score 7.7high
Affected software
TYPO3
Extension "Event management and registration"
pkg:composer/derhansen/sf_event_mgtRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The TYPO3 extension "Event management and registration" improperly neutralizes special elements used in its Fluid template engine. Specifically, an editor-configurable email subject string is injected directly into the Fluid template source without restriction. A backend user with edit access can inject Fluid ViewHelper syntax in this field, enabling disclosure of sensitive data or execution of TypoScript content objects. The vulnerability requires authenticated backend access with edit permissions. No official patch or remediation level is currently indicated.
Potential Impact
An attacker with authenticated backend access and edit permissions can exploit this vulnerability to disclose sensitive information or execute TypoScript content objects, potentially leading to unauthorized actions within the TYPO3 system. This elevates the risk of data leakage and unauthorized code execution within the affected extension.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, restrict backend user permissions to limit edit access to the event registration plugin or backend module to trusted users only.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- TYPO3
- Date Reserved
- 2026-08-20T13:10:12.062Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6a8d5b63acd9273b49f3656c
Added to database: 08/25/2026, 09:07:47 UTC
Last enriched: 09/10/2026, 06:52:15 UTC
Last updated: 10/10/2026, 06:48:19 UTC
Views: 49
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