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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| — | mautic/core | 1.3.0 – < 4.4.20, 5.0.0 – < 5.2.11, 6.0.0 – < 6.0.9, 7.0.0 – < 7.1.2 | 4.4.20 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
GitHub 2 repositories
-
covepseng/cve-2026-9558-poc ★ 1 · Jul 10, 2026
Exploitability PoC for CVE-2026-9558 (SSTI Mautic Theme)
-
Cimihan123/CVE-2026-9558-lab-poc-bundle ★ 0 · Oct 3, 2026
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Packagist | mautic/core | >= 1.3.0 | — | GHSA-9fx4-7cmj-47vg |
| Packagist | mautic/core | >= 5.0.0, < 5.2.11 | 5.2.11 | GHSA-9fx4-7cmj-47vg |
| Packagist | mautic/core | >= 6.0.0, < 6.0.9 | 6.0.9 | GHSA-9fx4-7cmj-47vg |
| Packagist | mautic/core | >= 7.0.0, < 7.1.2 | 7.1.2 | GHSA-9fx4-7cmj-47vg |
Advisories 1
- WID-SEC-2026-1724 Mautic: Mehrere Schwachstellen BSI CERT-Bund (WID) · May 31, 2026