CVE-2026-54623: django CMS Denial of Service Vulnerability

HIGH
Advisory Identifier: GHSA-8jj7-4v57-frf5
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CVSS 7.1
CWE-835 CWE-674
Published
Advisory Summary

CVE-2026-54623 is a HIGH (CVSS 7.1) denial of service vulnerability (CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')) affecting django CMS libraries in the PyPI ecosystem. The issue involves plugin move endpoint allows cyclic reparenting (dos). Remediation is available by upgrading affected packages to version 5.0.8.

CVE-2026-54623 at a Glance

CVE Identifier CVE-2026-54623
GHSA Identifier GHSA-8jj7-4v57-frf5
Severity HIGH
CVSS v3.1 Base Score 7.1
CWE Classification CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop')
Affected Product django CMS
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 7.1

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity Low (I:L)
Availability High (A:H)

How to Fix CVE-2026-54623

To remediate this vulnerability, upgrade all affected django CMS dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

django-cms fixed: 5.0.8 
pip install django-cms>=5.0.8
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show django-cms

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-54623, inspect your installed packages using pip:

pip show django-cms

Analyze the terminal output to locate any version of django CMS in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 5.0.8), your application is affected.

Note: The pip show django-cms command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop'), where the product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop. In django CMS, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### 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]).

CVE-2026-54623 Affected django CMS Versions

1 component(s)
Fixed Versions:
5.0.8
Product / Package Ecosystem Affected Versions Fixed Version
django-cms
pypi/django-cms
PyPI
< 5.0.8
5.0.8

References

GitHub Advisory / Wiki ADVISORY
https://github.com/django-cms/django-cms/security/advisories/GHSA-8jj7-4v57-frf5
NVD — CVE-2026-54623 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-54623
django CMS Source Repository REPOSITORY
https://github.com/django-cms/django-cms/pull/8645
Security Fix Commit FIX COMMIT
https://github.com/django-cms/django-cms/commit/7642a98ab3170793c0b27b4125dd1f3d318b8a1c
django CMS Source Repository REPOSITORY
https://github.com/django-cms/django-cms
django CMS Release RELEASE
https://github.com/django-cms/django-cms/releases/tag/5.0.8

Frequently Asked Questions

What is CVE-2026-54623?
CVE-2026-54623 is a security vulnerability in django CMS involving Plugin move endpoint allows cyclic reparenting (DoS) under CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop').
Which django CMS versions are affected?
Affected versions include releases prior to 5.0.8 across affected packages: django-cms.
What version fixes CVE-2026-54623?
Upgrading to 5.0.8 (or the latest patched release for your respective branch) resolves the vulnerability.
Is django-cms affected?
Yes, django-cms is affected in releases prior to 5.0.8. Upgrade your dependency to 5.0.8 or later.
What is the CVSS score of CVE-2026-54623?
CVE-2026-54623 has a CVSS v3.1 base score of 7.1 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H.
What CWE is associated with CVE-2026-54623?
CVE-2026-54623 is classified under CWE-835: Loop with Unreachable Exit Condition ('Infinite Loop') (The product contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.).
How can I check PyPI dependencies for CVE-2026-54623?
Run the dependency tree command: 'pip show django-cms'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-8jj7-4v57-frf5",
  "modified" : "2026-08-24T20:09:43Z",
  "published" : "2026-08-24T20:09:43Z",
  "aliases" : [ "CVE-2026-54623" ],
  "summary" : "django CMS: Plugin move endpoint allows cyclic reparenting (DoS)",
  "details" : "### Summary\nThe `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.\n\n### Details\n`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.\n\nDescendant 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.\n\n### Impact\nAn 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.\n\nRequires `CMS_PERMISSION`/plugin-change permission on a placeholder.\n\n### Patches\nFixed 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.\n\n### Workarounds\nNone. Upgrade is recommended.\n\n### Credits\nReported by the security team at the University of Sydney ([@reporter]).",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "django-cms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "5.0.8"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/django-cms/django-cms/security/advisories/GHSA-8jj7-4v57-frf5"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-54623"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/django-cms/django-cms/pull/8645"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/django-cms/django-cms/commit/7642a98ab3170793c0b27b4125dd1f3d318b8a1c"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/django-cms/django-cms"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/django-cms/django-cms/releases/tag/5.0.8"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-674", "CWE-835" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-08-24T20:09:43Z",
    "nvd_published_at" : "2026-08-20T18:16:28Z"
  }
}