by Kastro
Paper/Archive/CVE-2026-9558

CVE-2026-9558

Mautic — A Server-Side Template Injection (SSTI) vulnerability exists in Mautic's theme engine.

EPSS 0.6%CVSS 9.9
critical.is priorityof 100
39
CVSS 9.9 (CNA)9.9 / 10 × 3029.7Not in CISA KEV+300.0EPSS percentile 47.3.473 × 209.5No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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

ProductAffectedFixed inSource
mautic/core1.3.0 – < 4.4.204.4.20CNA
mautic/core5.0.0 – < 5.2.115.2.11CNA
mautic/core6.0.0 – < 6.0.96.0.9CNA
mautic/core7.0.0 – < 7.1.27.1.2CNA

Scores by source

Mautic (CNA)9.9CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: total

References

refgithub.com/mautic/mautic/security/advisories/GHSA-9fx4-7cmj-47vg