Medium

Decap CMS Cross Site Scripting (XSS) vulnerability

  • Disclosed: 10.09.2025
  • Updated: 11.10.2026 10:22

Decap CMS through 3.8.3 is vulnerable to stored Cross-Site Scripting (XSS) in the admin preview pane. User-controlled fields (e.g., title, description, tags, and body) are rendered in the preview without sufficient sanitization/escaping. An attacker with low-privilege author/contributor access can persist a JavaScript payload in content; when a maintainer or reviewer opens the preview, the payload executes in the CMS admin origin, enabling token/session theft or the execution of privileged actions via the DOM. The issue affects multiple input vectors and requires only passive interaction from the previewing user. As no patched version is available, administrators should restrict untrusted contributor roles and filter or disable preview rendering of untrusted HTML.

Affected software

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PlatformPackageVulnerable versionsFixed in
npm package decap-cms <= 3.8.3 no fix

References

CVSS score 6.1/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Weakness (CWE)
CWE-79
Platform
npm
Package
decap-cms
Disclosed
10.09.2025
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-xp8g-32qh-mv28 - CC BY 4.0

Vulnerability history: decap-cms

All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.

This is the only known vulnerability of this package.

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