CVE-2026-9558
Medium
Elevated severity or exploit probability.
CVSS base
9.9
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS — probability of exploitation (30 days)
0.8%
54.4th percentile
CISA KEV
Not listed
Weakness / dates
CWE-1336
Published 2026-05-29 · modified 2026-07-21
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.