django CMS: Page cache ignores plugin-declared Vary headers (disclosure & poisoning)

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

4.8 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

EPSS

• CVE-2026-54625: 0.18% estimated exploitation activity in the next 30 days; percentile 7.62 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary The CMS page cache key ignores the request headers that plugins declare via getvarycacheon(). The header is added to the response Vary header, but the CMS's own cache key does not incorporate the header values, so the first visitor's variant is served to all subsequent visitors regardless of their header values. Details pagecachekey (in cms/cache/page.py) keys only on cache prefix, site, language, path and timezone. setpagecache collects the plugin-declared vary headers and calls patchvaryheaders(response, ...) (affecting only the emitted Vary header), but stores and retrieves the cached page under the header-agnostic key. getpagecache therefore returns whichever variant was cached first. Impact - Information disclosure: when a plugin varies its output on a request header (e.g. Country-Code), the variant rendered for the first anonymous visitor is served to everyone until the entry expires, leaking request-specific content across users. - Cache poisoning: an unauthenticated…

Published by the source

24 Aug 2026, 20:09 UTC

Last modified by the source

24 Aug 2026, 20:09 UTC

Source last checked

26 Oct 2026, 13:50 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-fwjf-m4qw-9f2x

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# Patch Next advisory brief: CVE-2026-54625

Advisory: django CMS: Page cache ignores plugin-declared Vary headers (disclosure & poisoning)
IDs: CVE-2026-54625, GHSA-fwjf-m4qw-9f2x
Record: https://patchnext.com/advisories/cve-2026-54625 (revision 1, source checked 26 Oct 2026, 13:50 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: django-cms 5.0.8. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI django-cms: affected < 5.0.8; fixed in 5.0.8

## Suggested inspection (read-only)
- `python -m pip show django-cms`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on django-cms.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-fwjf-m4qw-9f2x (GitHub-reviewed advisory GHSA-fwjf-m4qw-9f2x lists affected ranges: PyPI django-cms >=0 <5.0.8)

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