Summary
django CMS: Plugin move endpoint allows cyclic reparenting (DoS)
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.
Workarounds
None. Upgrade is recommended.
Credits
Reported by the security team at the University of Sydney ([@reporter]).
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.
CVE-2026-54623 has a CVSS score of 7.1 (High). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (5.0.8); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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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.
Frequently Asked Questions
- What is CVE-2026-54623? CVE-2026-54623 is a high-severity security vulnerability in django-cms (pip), affecting versions < 5.0.8. It is fixed in 5.0.8.
- How severe is CVE-2026-54623? CVE-2026-54623 has a CVSS score of 7.1 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of django-cms are affected by CVE-2026-54623? django-cms (pip) versions < 5.0.8 is affected.
- Is there a fix for CVE-2026-54623? Yes. CVE-2026-54623 is fixed in 5.0.8. Upgrade to this version or later.
- Is CVE-2026-54623 exploitable, and should I be worried? Whether CVE-2026-54623 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-54623 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-54623? Upgrade
django-cmsto 5.0.8 or later.