CVE-2026-9558
CVSS Score
9.9
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-1336 |
| Published | May 29, 2026 |
| Last Updated | May 29, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High
References
Credits
Onurcan Genç (@onurcangnc) Daniel Zhang (@xfer0) Tuan Do (@Entropt) Patryk Gruszka (@patrykgruszka) John Linhart (@escopecz) Leuchtfeuer Digital Marketing (@Leuchtfeuer)