CVE-2026-54623

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.

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.

Summary

The move_plugin admin endpoint does not prevent a plugin from being reparented under itself or one of its own descendants. Doing so creates a cycle in the plugin tree, after which the recursive descendant/ancestor SQL queries loop without terminating, stalling the request worker.

Details

move_plugin (in cms/admin/placeholderadmin.py) accepts a plugin_parent POST parameter and, for an in-placeholder move, sets the plugin's parent to the target without any cycle/ancestor check. If the target parent is a descendant of the moved plugin, the resulting parent_id graph contains a cycle.

Descendant and ancestor traversal is implemented with WITH RECURSIVE CTEs (_get_descendants_cte / _get_ancestors_cte in cms/models/pluginmodel.py) that have no cycle clause or depth limit. On a cyclic tree these recurse indefinitely (PostgreSQL/SQLite) or error at the recursion limit (MySQL). get_descendants() is invoked while building the move response and on subsequent operations on the affected subtree.

Impact

An authenticated staff user with permission to change plugins in at least one placeholder can corrupt that placeholder's plugin tree, causing requests that traverse it (rendering, copy, delete) to hang and consume application workers (denial of service). The tree is also left in a corrupted state.

Requires CMS_PERMISSION/plugin-change permission on a placeholder.

Patches

Fixed in 5.0.8: move_plugin now rejects (HTTP 400) any move that would place a plugin inside itself or one of its descendants, before any tree mutation or traversal.

Workarounds

None. Upgrade is recommended.

Credits

Reported by the security team at the University of Sydney ([@reporter]).

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.

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.

Summary

The move_plugin admin endpoint does not prevent a plugin from being reparented under itself or one of its own descendants. Doing so creates a cycle in the plugin tree, after which the recursive descendant/ancestor SQL queries loop without terminating, stalling the request worker.

Details

move_plugin (in cms/admin/placeholderadmin.py) accepts a plugin_parent POST parameter and, for an in-placeholder move, sets the plugin's parent to the target without any cycle/ancestor check. If the target parent is a descendant of the moved plugin, the resulting parent_id graph contains a cycle.

Descendant and ancestor traversal is implemented with WITH RECURSIVE CTEs (_get_descendants_cte / _get_ancestors_cte in cms/models/pluginmodel.py) that have no cycle clause or depth limit. On a cyclic tree these recurse indefinitely (PostgreSQL/SQLite) or error at the recursion limit (MySQL). get_descendants() is invoked while building the move response and on subsequent operations on the affected subtree.

Impact

An authenticated staff user with permission to change plugins in at least one placeholder can corrupt that placeholder's plugin tree, causing requests that traverse it (rendering, copy, delete) to hang and consume application workers (denial of service). The tree is also left in a corrupted state.

Requires CMS_PERMISSION/plugin-change permission on a placeholder.

Patches

Fixed in 5.0.8: move_plugin now rejects (HTTP 400) any move that would place a plugin inside itself or one of its descendants, before any tree mutation or traversal.

Workarounds

None. Upgrade is recommended.

Credits

Reported by the security team at the University of Sydney ([@reporter]).

Summary

The move_plugin admin endpoint does not prevent a plugin from being reparented under itself or one of its own descendants. Doing so creates a cycle in the plugin tree, after which the recursive descendant/ancestor SQL queries loop without terminating, stalling the request worker.

Details

move_plugin (in cms/admin/placeholderadmin.py) accepts a plugin_parent POST parameter and, for an in-placeholder move, sets the plugin's parent to the target without any cycle/ancestor check. If the target parent is a descendant of the moved plugin, the resulting parent_id graph contains a cycle.

Descendant and ancestor traversal is implemented with WITH RECURSIVE CTEs (_get_descendants_cte / _get_ancestors_cte in cms/models/pluginmodel.py) that have no cycle clause or depth limit. On a cyclic tree these recurse indefinitely (PostgreSQL/SQLite) or error at the recursion limit (MySQL). get_descendants() is invoked while building the move response and on subsequent operations on the affected subtree.

Impact

An authenticated staff user with permission to change plugins in at least one placeholder can corrupt that placeholder's plugin tree, causing requests that traverse it (rendering, copy, delete) to hang and consume application workers (denial of service). The tree is also left in a corrupted state.

Requires CMS_PERMISSION/plugin-change permission on a placeholder.

Patches

Fixed in 5.0.8: move_plugin now rejects (HTTP 400) any move that would place a plugin inside itself or one of its descendants, before any tree mutation or traversal.

Workarounds

None. Upgrade is recommended.

Credits

Reported by the security team at the University of Sydney ([@reporter]).