CVE-2026-23630: Docmost is vulnerable to stored Cross-Site Scripting (XSS) through Mermaid rendering

Published Jan 21, 2026
·
Updated

Docmost is open-source collaborative wiki and documentation software. In versions 0.3.0 through 0.23.2, Mermaid code block rendering is vulnerable to stored Cross-Site Scripting (XSS). The frontend can render attacker-controlled Mermaid diagrams using mermaid.render(), then inject the returned SVG/HTML into the DOM via dangerouslySetInnerHTML without sanitization. Mermaid per-diagram %%{init}%% directives allow overriding securityLevel and enabling htmlLabels, permitting arbitrary HTML/JS execution for any viewer. This issue has been fixed in version 0.24.0.

Affected Software

2 affected components
npm/docmost>=0.3.0<0.23.2
docmost docmost>=0.3.0<0.24.0

Event History

Jan 21, 2026
CVE Published
via MITRE·10:51 PM
Data Sourced
via MITRE·10:51 PM
DescriptionWeakness
Data Sourced
via NVD·11:15 PM
RemedyDescriptionSeverityWeaknessAffected Software

Frequently Asked Questions

1

What is the severity of CVE-2026-23630?

CVE-2026-23630 is classified as a high severity vulnerability due to its potential for stored Cross-Site Scripting (XSS) attacks.

2

How do I fix CVE-2026-23630?

To fix CVE-2026-23630, upgrade to Docmost version 0.24.0 or later where the vulnerability has been addressed.

3

What versions of Docmost are affected by CVE-2026-23630?

Versions 0.3.0 through 0.23.2 of Docmost are affected by CVE-2026-23630.

4

What type of vulnerability is CVE-2026-23630?

CVE-2026-23630 is a stored Cross-Site Scripting (XSS) vulnerability.

5

Can CVE-2026-23630 lead to data compromise?

Yes, CVE-2026-23630 can lead to data compromise through the execution of malicious scripts on user systems.

Contact

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