CVE-2026-54623 in django CMS
Summary
by MITRE • 08/20/2026
django CMS is an easy-to-use and developer-friendly enterprise content management system powered by Django. Prior to 5.0.8, the move_plugin endpoint in cms/admin/placeholderadmin.py accepts an attacker-controlled plugin_parent value without rejecting a plugin’s own identifier or a descendant identifier. A staff user with plugin-change permission under CMS_PERMISSION can create a parent_id cycle in the plugin tree. The _get_descendants_cte and _get_ancestors_cte queries in cms/models/pluginmodel.py have no cycle guard, so get_descendants() and later rendering, copy, or delete operations can recurse indefinitely or reach a database recursion limit, corrupting the tree and consuming request workers. This issue is fixed in versions 5.0.8.
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Analysis
by VulDB Data Team • 08/20/2026
django CMS version 5.0.7 and earlier contain a critical logic flaw within the plugin management subsystem that allows for the creation of circular references in the plugin hierarchy, leading to denial of service conditions through infinite recursion or database resource exhaustion. The vulnerability resides specifically in the move_plugin endpoint located at cms/admin/placeholderadmin.py, which is responsible for reordering plugins within a placeholder structure. Under normal operational parameters, this endpoint should validate that a parent identifier does not correspond to the plugin being moved or any of its existing descendants to maintain an acyclic tree structure. However, prior to version 5.0.8, the validation logic fails to reject cases where the attacker-controlled plugin_parent value matches either the identifier of the plugin itself or one of its descendant plugins. This oversight permits a staff user possessing only standard plugin-change permissions under CMS_PERMISSION settings to inject circular dependencies into the data model.
The technical root cause is compounded by deficiencies in the recursive query mechanisms defined within cms/models/pluginmodel.py, specifically the _get_descendants_cte and _get_ancestors_cte functions. These Common Table Expressions are designed to traverse the plugin tree hierarchy but lack any cycle detection guards or depth limits. When a circular reference exists due to the aforementioned validation bypass, invoking methods such as get_descendants() triggers an infinite loop during execution. This behavior is not limited to simple retrieval operations; it also impacts subsequent administrative actions including rendering pages in the frontend, copying plugins, or deleting them from the database. The system attempts to traverse the cycle indefinitely until it either hits a hard recursion limit imposed by the Python interpreter or exhausts available memory and CPU cycles on the web server.
The operational impact of this vulnerability is severe, primarily manifesting as a denial of service against the django CMS instance. Because the recursive traversal consumes significant computational resources without returning results, request workers become blocked waiting for these operations to complete or fail. In environments with limited worker pools, such as those using synchronous WSGI servers like Gunicorn in default configurations, this can lead to thread exhaustion where no new requests are processed until the stuck threads time out or are killed by an external process manager. Furthermore, repeated attempts to access corrupted plugin trees may cause database errors if the underlying SQL engine imposes stricter recursion limits than the application layer, potentially leading to transaction rollbacks and data inconsistency within the CMS content store.
This vulnerability aligns with CWE-835, which describes a loop involving unnecessary consumption of resources, as well as CWE-611 regarding Improper Restriction of XML External Entity References if interpreted broadly in terms of structural integrity violations, though it is most accurately categorized under logic flaws that lead to resource exhaustion. From an ATT&CK perspective, this behavior facilitates the Disruption or Denial of Service tactic by allowing a low-privileged user to degrade system availability without requiring elevated privileges or complex exploitation techniques beyond standard administrative interface interaction. The attack vector is local in nature relative to authentication requirements but remote if the admin panel is exposed to the internet with weak access controls.
Mitigation strategies focus primarily on upgrading to django CMS version 5.0.8 or later, where the move_plugin endpoint has been patched to strictly validate parent-child relationships and prevent circular references at the application layer. For organizations unable to upgrade immediately due to dependency constraints, temporary mitigations include restricting administrative access through robust firewall rules or reverse proxy configurations that limit exposure of the admin interface to trusted IP ranges only. Additionally, implementing database-level triggers or stored procedures to enforce acyclic graph constraints can provide a secondary defense line, although this requires careful schema modification and testing to avoid performance degradation on legitimate large-scale plugin trees. Regular auditing of CMS permissions ensures that users with write access are strictly monitored, reducing the attack surface for internal privilege abuse scenarios.