CVE-2026-77129
Server-Side Template Injection in extension "Event management and registration" (sf_event_mgt)
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.
INFO
Published Date :
Aug. 25, 2026, 9:17 a.m.
Last Modified :
Aug. 25, 2026, 9:17 a.m.
Remotely Exploit :
Yes !
Source :
f4fb688c-4412-4426-b4b8-421ecf27b14a
Affected Products
The following products are affected by CVE-2026-77129
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 4.0 | HIGH | f4fb688c-4412-4426-b4b8-421ecf27b14a | ||||
| CVSS 4.0 | HIGH | f4fb688c-4412-4426-b4b8-421ecf27b14a |
Solution
- Validate and sanitize all user-supplied input.
- Update the extension to the latest version.
- Restrict backend user privileges if possible.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-77129.
| URL | Resource |
|---|---|
| https://typo3.org/security/advisory/typo3-ext-sa-2026-023 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-77129 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-77129
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-77129 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-77129 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by f4fb688c-4412-4426-b4b8-421ecf27b14a
Aug. 25, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://github.com/derhansen/sf_event_mgt', 'vendor': 'TYPO3', 'product': 'Extension "Event management and registration"', 'versions': [{'status': 'affected', 'version': '9.0.0', 'lessThan': '9.0.3', 'versionType': 'semver'}, {'status': 'affected', 'version': '8.0.0', 'lessThan': '8.6.2', 'versionType': 'semver'}, {'status': 'affected', 'version': '7.0.0', 'lessThan': '7.9.3', 'versionType': 'semver'}, {'status': 'affected', 'version': '6.0.0', 'lessThan': '6.7.2', 'versionType': 'semver'}, {'status': 'affected', 'version': '0', 'lessThan': '5.9.3', 'versionType': 'semver'}], 'packageName': 'derhansen/sf_event_mgt', 'collectionURL': 'https://packagist.org/', 'defaultStatus': 'unaffected'}] Added 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. Added CVSS V4.0 AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-1336 Added Reference https://typo3.org/security/advisory/typo3-ext-sa-2026-023