Stored Cross-Site Scripting Vulnerability in Movable Type by Six Apart
CVE-2026-21393
4.8MEDIUM
What is CVE-2026-21393?
Movable Type is impacted by a stored cross-site scripting vulnerability found in the Edit Comment functionality. If an attacker inputs crafted data, it can be stored and later executed as arbitrary script in the web browsers of users who are logged in. This vulnerability is particularly concerning for users of the Movable Type 7 and 8.4 series, which are noted as End-of-Life (EOL), leaving them open to exploitation.
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
CVSS V4
Score:
4.8
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:
5.4
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