Arbitrary file upload in Six Apart Ltd products - CVE-2026-23704
Published: February 4, 2026
Vulnerability identifier: #VU122294
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-23704
CWE-ID: CWE-434
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Six Apart Ltd
Affected software:
Movable Type
Movable Type Advanced
Movable Type Premium
Movable Type Premium (Advanced Edition)
Movable Type Cloud Edition
Movable Type Premium Cloud Edition
Movable Type
Movable Type Advanced
Movable Type Premium
Movable Type Premium (Advanced Edition)
Movable Type Cloud Edition
Movable Type Premium Cloud Edition
Detailed vulnerability description
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to insufficient validation of file during file upload. A remote user can upload a malicious file and execute it on the server.
How to mitigate CVE-2026-23704
Install updates from vendor's website.