File Upload Vulnerability in Movable Type by Six Apart
CVE-2026-23704

5.1MEDIUM

Key Information:

Vendor

Six Apart Ltd.

Status
Movable Type (software Edition)
Movable Type Advanced (software Edition)
Movable Type Premium (software Edition)
Movable Type Premium (advanced Edition) (software Edition)
Vendor
CVE Published:
4 February 2026

What is CVE-2026-23704?

A vulnerability exists in Movable Type that allows non-administrative users to upload malicious files. If these files are accessed by an administrator or other privileged users, it can result in the execution of arbitrary scripts in the administrator's browser. This vulnerability notably affects both the End-of-Life (EOL) 7 series and 8.4 series of Movable Type products, posing a significant risk for users still utilizing these versions.

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Affected Version(s)

Movable Type (Cloud Edition) 9.0.5 (9 series)

Movable Type (Cloud Edition) 8.8.1 (8 series)

Movable Type (Software Edition) 9.0.4 to 9.0.5 (9.0 series)

References

https://movabletype.org/news/2026/02/mt-906-released.html
https://www.sixapart.jp/movabletype/news/2026/02/04-1100....
https://jvn.jp/en/jp/JVN45405689/

CVSS V4

Score:
5.1
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

CVSS V3.0

Score:
6.5
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
Required
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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