Stored Cross-Site Scripting Vulnerability in Movable Type by Six Apart
CVE-2025-54856

4.6MEDIUM

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:
23 October 2025

What is CVE-2025-54856?

Movable Type has a stored cross-site scripting vulnerability present in the Edit ContentData page. An attacker with 'ContentType Management' rights can input malicious scripts, which are then stored and can execute in the web browser of any user who later accesses the Edit ContentData page. This vulnerability can lead to unauthorized actions performed on behalf of the users, exposing sensitive data and potentially compromising site integrity.

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Affected Version(s)

Movable Type (Cloud Edition) 8.7.0 (8 series)

Movable Type (Cloud Edition) 7 r.5509 (7 series)

Movable Type (Software Edition) 8.4.0 to 8.4.3 (8.4 series)

References

https://movabletype.org/news/2025/10/mt-880-released.html
https://www.sixapart.jp/movabletype/news/2025/10/22-1055....
https://jvn.jp/en/jp/JVN24333679/

CVSS V4

Score:
4.6
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:
4.8
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
High
User Interaction:
Required
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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