CVE-2026-9558

CRITICAL EPSS 35.1%

Published May 29, 20261mo ago · Modified Jun 17, 20261w ago

9.9 CVSS 3.1

Critical

Published May 29, 2026 1mo ago

Last Modified Jun 17, 2026 1w ago

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.

CVSS Details

Base Score

9.9

Exploitability

3.1

Impact

6.0

Vector string

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

Threat Intelligence

EPSS Exploit Probability

35.1% percentile

Exploit & Patch Status

No Known Exploit

No Patch Available

Weaknesses 1

CWE-1336

References 1

github.com https://github.com/mautic/mautic/security/advisories/GHSA-9fx4-7cmj-47vg

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.