Critical

Mautic has Server-Side Template Injection (SSTI) in Theme Templates

  • Disclosed: 02.07.2026
  • Updated: 11.10.2026 10:22

Summary

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.

Impact

An authenticated user with theme upload and creation privileges can bypass boundaries to execute arbitrary system commands on the hosting server (Remote Code Execution) or access restricted system files and configuration settings.

Patched Versions

This security issue has been addressed in the following releases:

  • 7.1.2
  • 6.0.9
  • 5.2.11

For users on Mautic 4.x, this fix is available in:

Mautic strongly recommend upgrading to a patched version immediately.

Workarounds

There are no official workarounds. To mitigate this vulnerability without upgrading, restrict theme upload and creation permissions (core:themes:create) to only highly trusted administrators.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Composer package mautic/core >= 1.3.0, >= 5.0.0, < 5.2.11, >= 6.0.0, < 6.0.9, >= 7.0.0, < 7.1.2 5.2.11, 6.0.9, 7.1.2

References

CVSS score 9.9/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Weakness (CWE)
CWE-1336
Platform
Composer
Package
mautic/core
Disclosed
02.07.2026
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-9fx4-7cmj-47vg - CC BY 4.0

Vulnerability history: mautic/core

All published vulnerabilities of this package (Composer package), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (57) in the archive
Total entries
57
First → latest
01.2021 07.2026
Without a fix
1
Exploited in attacks
0

Severity breakdown

  • Critical 9
  • High 17
  • Medium 29
  • Low 2

Disclosures per year

  1. 2021: 16
  2. 2022: 7
  3. 2023: 0
  4. 2024: 13
  5. 2025: 13
  6. 2026: 8
Severity:
  1. High · 7.6 CVE-2026-9809 >= 7.0.0, < 7.1.2 7.1.2
  2. High · 7.1 CVE-2026-9808 >= 7.0.0, < 7.1.2 7.1.2
  3. Critical · 9.9 CVE-2026-9559 >= 7.0.0, < 7.1.2 7.1.2
  4. Mautic has Server-Side Template Injection (SSTI) in Theme Templates this entry
    Critical · 9.9 CVE-2026-9558 >= 1.3.0, >= 5.0.0, < 5.2.11, >= 6.0.0, < 6.0.9, >= 7.0.0, < 7.1.2 5.2.11, 6.0.9, 7.1.2
  5. High · 7.1 CVE-2026-4776 >= 2.6.0, <= 4.4.13, >= 5.0.0, < 5.2.11, >= 6.0.0, < 6.0.9, >= 7.0.0, < 7.1.2 5.2.11, 6.0.9, 7.1.2
  6. High · 7.6 CVE-2026-3105 >= 2.10.0, < 5.2.10, >= 6.0.0-alpha, < 6.0.8, >= 7.0.0-alpha, < 7.0.1 5.2.10, 6.0.8, 7.0.1
  7. Critical CVE-2025-13828 >= 4.0.0, < 4.4.18, >= 5.0.0, < 5.2.9, >= 6.0.0, < 6.0.7 4.4.18, 5.2.9, 6.0.7
  8. High · 7.7 CVE-2024-47053 >= 1.0.1, < 5.2.3 5.2.3
  9. Critical · 9.1 CVE-2024-47051 < 5.2.3 5.2.3
  10. High · 7.0 CVE-2022-25768 >= 1.1.3, < 4.4.13, >= 5.0.0-alpha, < 5.1.1 4.4.13, 5.1.1
  11. Critical · 9.6 CVE-2020-35125 < 2.16.5, >= 3.0.0, < 3.2.4 2.16.5, 3.2.4
  12. High · 8.3 CVE-2022-25776 >= 1.0.2, < 4.4.12, >= 5.0.0-alpha, < 5.0.4 4.4.12, 5.0.4
  13. High · 8.1 CVE-2021-27916 >= 3.3.0, < 4.4.12, >= 5.0.0-alpha, < 5.0.4 4.4.12, 5.0.4
  14. High · 7.6 CVE-2021-27915 >= 1.0.0-beta2, < 4.4.12 4.4.12
  15. Critical · 9.0 CVE-2020-35129 < 3.2.4 3.2.4
  16. Critical · 9.0 CVE-2020-35128 >= 3.2.0, < 3.2.4, >= 2.0.0, < 2.16.5 3.2.4, 2.16.5
  17. High · 7.5 CVE-2017-1000046 < 2.1.1 2.1.1
  18. High · 8.8 CVE-2017-8874 = 1.4.1 no fix
  19. High · 8.2 CVE-2021-27910 < 3.3.4, >= 4.0.0-alpha1, < 4.0.0 3.3.4, 4.0.0
Show more (6) Showing 20 of 26

Know which vulnerabilities affect your application

With the DockRay integration and software inventory enabled, DockRay checks reported component versions against known vulnerabilities and notifies you about confirmed matches. Coverage depends on the supported technology and available advisory data.

Connect your application
DockRay newsletter

Application security in your inbox

Important vulnerabilities, actionable guidance and practical advice for your applications. Choose your technologies and follow what matters to your project.

  • A daily digest of new vulnerabilities, critical ones included.
  • Notifications about important updates.
  • Practical advice on application security and monitoring.

Leave empty to receive updates for every technology.

Free to subscribe. Unsubscribe with one click in any email.