GHSA-hvq6-2r72-p2x7 is a medium-severity (CVSS 4.4) Cross-site Scripting (XSS) vulnerability in django-cms. A fix is available for django-cms — see the affected versions and patch details below.
django CMS: Stored XSS in edit-mode plugin exception rendering
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-hvq6-2r72-p2x7.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
GHSA-hvq6-2r72-p2x7 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 382,621 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
django-cmsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Summary
When plugin rendering fails in edit mode, django CMS renders a cms-rendering-exception block so editors can see that a placeholder could not be rendered. Older code built that block's heading by interpolating the exception message, placeholder/source strings, and the failing plugin's short description directly into an HTML string, then returned the placeholder output as safe markup.
If an editor could store HTML in data used by a plugin's get_short_description() (or in other values interpolated into the exception message), and that plugin later raised during edit-mode rendering, the payload was parsed as HTML in the staff user's browser. This is a stored XSS condition in the CMS editing context.
Impact
The vulnerable path is only reached when placeholder rendering catches a plugin rendering exception:
try:
placeholder_content = "".join(plugin_content)
except Exception as e:
context["exc_info"] = sys.exc_info()
placeholder_content = self.render_exception("rendering placeholder", context, placeholder, editable)
render_exception() constructs a message from values that can include stored content:
value- the exception message.placeholder- the placeholder string representation.placeholder.source- the source object string representation, such as page content.instance.get_short_description()- plugin-provided summary text, often derived from plugin model fields.
In the vulnerable implementation, that message was embedded directly into an HTML heading. The final placeholder content was later returned through mark_safe, so Django template autoescaping did not protect the heading.
settings.DEBUG does not mitigate the issue: it only controls whether Django's traceback HTML is appended. The custom heading is rendered in edit mode regardless of DEBUG.
Patch
Escape the custom exception heading before returning it as safe placeholder markup. The current fixed code uses format_html, which escapes message before inserting it into the heading:
heading = format_html('<h2 class="cms-rendering-exception-title">{}</h2>', message)
The traceback HTML from ExceptionReporter.get_traceback_html() should remain separate from django CMS's custom heading; Django's traceback escaping does not protect additional HTML assembled by django CMS.
Workarounds
Until patched, reduce exposure by ensuring only fully trusted staff can edit plugins whose stored fields are included in get_short_description(), and fix or disable plugins that can be made to raise during edit-mode rendering. This is only a partial mitigation because the escaping bug is in the shared exception-rendering path.
References
cms/plugin_rendering.py-ContentRenderer.render_placeholdercms/plugin_rendering.py-ContentRenderer.render_exception- Fixed code:
heading = format_html('<h2 class="cms-rendering-exception-title">{}</h2>', message) - Regression tests:
cms.tests.test_plugin_renderers.TestExceptionCatchers.test_exception_in_plugin_render_escapes_user_content_in_edit_mode,cms.tests.test_plugin_renderers.TestLegacyRendererExceptionCatcher.test_exception_in_plugin_render_escapes_user_content_in_edit_mode
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | django-cms | ≥ 5.0.8&&< 5.0.9 | 5.0.9pip install --upgrade 'django-cms==5.0.9' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for django-cms, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update django-cms to 5.0.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-hvq6-2r72-p2x7 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Frequently Asked Questions
Is GHSA-hvq6-2r72-p2x7 in your dependencies?
Find it across PyPI, including transitive dependencies.