CVE-2026-115189

Server‑Side Template Injection in Mautic Twig Theme Rendering Allows Arbitrary Code Execution

Published Oct 26, 2026 CVSS 3.1 · 8.8 High EPSS < 1% KEV · Not listed
Description
A server-side template injection vulnerability exists in the Twig theme rendering sandbox of Mautic. The sandbox introduced to restrict user-uploaded theme templates (the fix for GHSA-9fx4-7cmj-47vg) does not fully enforce its restrictions, allowing a crafted theme template to escape the sandbox. An authenticated user with the core:themes:create permission can upload a malicious theme whose template is later rendered, resulting in execution of arbitrary code on the server with the privileges of the web server process. This allows the attacker to execute operating system commands, read server-side files including configuration files and database credentials, write files, and reach internal services. In default installations the core:themes:create permission is granted to the Administrator role, and in multi-operator setups it may be delegated to other roles. This is an incomplete fix for GHSA-9fx4-7cmj-47vg.

Remediation

Vendor Workaround

There are no official workarounds. To mitigate this vulnerability without upgrading, restrict the core:themes:create permission to trusted administrator accounts only and do not delegate theme creation to operator-level roles.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Mautic
Mautic mautic
Vendors & Products Mautic
Mautic mautic
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title Server‑Side Template Injection in Mautic Twig Theme Rendering Allows Arbitrary Code Execution
Type Values Removed Values Added
Description A server-side template injection vulnerability exists in the Twig theme rendering sandbox of Mautic. The sandbox introduced to restrict user-uploaded theme templates (the fix for GHSA-9fx4-7cmj-47vg) does not fully enforce its restrictions, allowing a crafted theme template to escape the sandbox. An authenticated user with the core:themes:create permission can upload a malicious theme whose template is later rendered, resulting in execution of arbitrary code on the server with the privileges of the web server process. This allows the attacker to execute operating system commands, read server-side files including configuration files and database credentials, write files, and reach internal services. In default installations the core:themes:create permission is granted to the Administrator role, and in multi-operator setups it may be delegated to other roles. This is an incomplete fix for GHSA-9fx4-7cmj-47vg.
Weaknesses CWE-1336
References
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
Mautic
Published
Updated
Oct 26, 2026, 3:35 PM
Reserved
Oct 22, 2026, 6:39 AM
Status
Deferred
Published
Oct 26, 2026, 2:16 PM
Modified
Oct 26, 2026, 4:17 PM