Review reviewHigh

CVE-2026-65693

microweber

Microweber CMS through 2.0.20 contains a server-side template injection vulnerability that allows authenticated administrators to achieve arbitrary OS command execution by injecting Twig expressions into mail templates. Attackers can exploit the unsandboxed Twig environment in TwigView::render(), which lacks SandboxExtension or a SecurityPolicy, to inject malicious expressions such as filter('system') into mail template bodies stored unsanitized in the database, causing automatic payload execution on each subsequent application event that triggers a mail dispatch.

CVSS: 8.6
EPSS: -
CISA KEV: Not listed
Published: 2026.07.25

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability-

Technical severityCVSS 8.6

Vulnerability overview

Affected product and versions

Product: microweber
Affected versions: <= 2.0.20
Fixed versions: No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that microweber and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CWE: CWE-94