VulnerabilityAnalyzed

CVE-2026-23630

In versions 0.3.0 through 0.23.2, Mermaid code block rendering is vulnerable to stored Cross-Site Scripting (XSS).

MEDIUM 6.3EPSS 0.25%

Does this matter?

Lower severity and a low EPSS score (0.25%). Track it; it rarely justifies an emergency change on its own.

Description

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.

CVSS 4.0: 6.3 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.25% probability · 17th percentile
CISA KEV: Not listed
Weakness: CWE-79, CWE-116
Affected: docmost/docmost
Source: security-advisories@github.com

References

https://github.com/docmost/docmost/commit/cb9f27da9a8b4940760e37e5238a1eb91e427dafPatch
https://github.com/docmost/docmost/releases/tag/v0.24.0Product, Release Notes
https://github.com/docmost/docmost/security/advisories/GHSA-r4hj-mc62-jmwjExploit, Vendor Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.