CVE-2026-9558

criticalpriority · track · 10EPSS 0.006 · 47 %ileexploit · PoCDEEUUS

grimoire priorityP1 · Urgent

Exploitable?

Public exploit

1 exploit · PoC

Likely / severe?

0.57% (47th) EPSS

CVSS 9.9 · critical

Is it mine?

12 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · cert_bund · osv

EPSS · scored 2026-10-27

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

Technical severity, 0–10. One row per scoring source.

9.9

010

base score 0–10 · higher = more severe · hover a vector to decode

v3.19.9criticalCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:Hsecondary · ENISA EU

v3.19.9criticalCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:Hsecondary · security@mautic.orgexploitability 3.1 · impact 6

v3.19.9criticalCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:Hsecondary · OSV

v3.19.4criticalCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:Psecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-1336USCWE-1336US

exploits (1)

Public proof-of-concept and weaponised exploit code.

covepseng/cve-2026-9558-pocExploitability PoC for CVE-2026-9558 (SSTI Mautic Theme)PoC · poc_in_github

affected products (12)

Products and version ranges known to be affected.

Open Source Mautic <4.4.20all versionscert_bundDE
Open Source Mautic <5.2.11all versionscert_bundDE
Open Source Mautic <6.0.9all versionscert_bundDE
Open Source Mautic <7.1.2all versionscert_bundDE
Open Source Mautic< 4.4.20cert_bundDE
Open Source Mautic< 5.2.11cert_bundDE
Open Source Mautic< 6.0.9cert_bundDE
Open Source Mautic< 7.1.2cert_bundDE
Packagist mautic/core≥ 1.3.0osvUSpkg:composer/mautic/core
Packagist mautic/core5.0.0 → 5.2.11osvUSpkg:composer/mautic/core
Packagist mautic/core6.0.0 → 6.0.9osvUSpkg:composer/mautic/core
Packagist mautic/core7.0.0 → 7.1.2osvUSpkg:composer/mautic/core

advisories (2)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2026-1724Mautic: Mehrere SchwachstellenDeutsch2026-05-28csaf · cert_bundDE
Ein entfernter, authentisierter Angreifer kann mehrere Schwachstellen in Mautic ausnutzen, um SQL-Injection- und Server-Side Request Forgery (SSRF)-Angriffe durchzuführen und um Informationen offenzulegen, beliebigen JavaScript-Code im Browser anderer Benutzer auszuführen, Dateien außerhalb vorgesehener Verzeichnisse einzubinden oder zu manipulieren sowie unter Umständen beliebigen Code auf dem Server auszuführen.
GHSA-9fx4-7cmj-47vgMautic has Server-Side Template Injection (SSTI) in Theme Templates2026-07-02ghsa · osvUS
### 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: * **4.4.20** via [ELTS](https://mautic.org/extended-long-term-support-elts/) 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.

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd cert_bund osv NVD CVE.org MITRE

published 2026-05-29modified 2026-07-21

references (3)

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan