VULNERABILITY INTELLIGENCE
CVE-2026-9558
CVSS score9.9 CRITICAL
EPSS probability0.57%
CISA KEVNot currently listed
Published2026-05-29
Last modified2026-07-21
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Description
A Server-Side Template Injection (SSTI) vulnerability exists in Mautic's theme engine. The platform renders uploaded Twig templates without a sandbox or strict function restrictions. Authenticated users with permissions to create or upload themes can abuse this to execute arbitrary code on the hosting server (Remote Code Execution) or access restricted system files and configuration settings.
Weakness classification
- CWE-1336: Improper Neutralization of Special Elements Used in a Template Engine