What’s Vulnerable › Vulnerabilities

CVE-2026-75526: django CMS: Stored XSS in edit-mode plugin exception rendering

• Severity: medium (CVSS 4.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-20 · updated 2026-10-26
• Weakness: CWE-79

Description

django CMS is an easy-to-use and developer-friendly enterprise content management system powered by Django. From 5.0.8 until 5.0.9, ContentRenderer.render_placeholder in cms/plugin_rendering.py can pass stored, attacker-controlled values to ContentRenderer.render_exception when plugin rendering fails in edit mode. Values from get_short_description(), the exception message, the placeholder, or placeholder.source are interpolated into a cms-rendering-exception heading and later returned through mark_safe. Because the heading is not escaped, stored HTML executes in an editor’s browser, and settings.DEBUG does not prevent the custom heading from rendering. The fix uses format_html to escape the message before safe placeholder output is returned. This issue is fixed in versions 5.0.9.

Affected products

• django-cms: from 5.0.8, < 5.0.9

References

• https://github.com/django-cms/django-cms/commit/b56a568844ff3702495945f73a31d0868285bf88
• https://github.com/django-cms/django-cms/pull/8711
• https://github.com/django-cms/django-cms/releases/tag/5.0.9
• https://github.com/django-cms/django-cms/security/advisories/GHSA-hvq6-2r72-p2x7

Get alerted when CVE-2026-75526 or the next vulnerability affects your stack