CVE-2026-21393 - Vulnerability Details - OpenCVE

Movable Type contains a stored cross-site scripting vulnerability in Edit Comment. If crafted input is stored by an attacker, arbitrary script may be executed on a logged-in user's web browser. Note that Movable Type 7 series and 8.4 series, which are End-of-Life (EOL), are affected by the vulnerability as well.

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Attack Requirements None

User Interaction Active

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact Low

Subsequent System Integrity Impact Low

Subsequent System Availability Impact None

No CVSS v3.1

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Scope Changed

Confidentiality Impact Low

Integrity Impact Low

Availability Impact None

User Interaction Required

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

No data.

No data.

No data.

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References

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

History

Wed, 04 Feb 2026 07:15:00 +0000

Type	Values Removed	Values Added
Description		Movable Type contains a stored cross-site scripting vulnerability in Edit Comment. If crafted input is stored by an attacker, arbitrary script may be executed on a logged-in user's web browser. Note that Movable Type 7 series and 8.4 series, which are End-of-Life (EOL), are affected by the vulnerability as well.
Weaknesses		CWE-79
References		https://jvn.jp/en/jp/JVN45405689/ https://movabletype.org/news/2026/02/mt-906-released.html https://www.sixapart.jp/movabletype/news/2026/02/04-1100.html
Metrics		cvssV3_0 `{'score': 5.4, 'vector': 'CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N'}` cvssV4_0 `{'score': 4.8, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N'}`

MITRE

Status: PUBLISHED

Assigner: jpcert

Published: 2026-02-04T07:02:50.465Z

Updated: 2026-02-04T07:02:50.465Z

Reserved: 2026-01-29T02:02:32.381Z

Link: CVE-2026-21393

Vulnrichment

No data.

NVD

Status : Received

Published: 2026-02-04T07:16:01.027

Modified: 2026-02-04T07:16:01.027

Link: CVE-2026-21393

Redhat

No data.

OpenCVE Enrichment

No data.

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