GHSA-8pcw-h6w9-h46g plone.app.contenttypes has a Denial of Service in File Upload due to excessive filename length
An attacker with content creation privileges can cause denial of service by uploading files with excessively long filenames, making the UI unresponsive.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is GHSA-8pcw-h6w9-h46g?
GHSA-8pcw-h6w9-h46g is a denial of service vulnerability in plone-app-contenttypes, published on 23 Sep 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Impact
When creating an Image or File with a very large filename, Plone can become unresponsive. Even if the content loads, it can be hard to edit or delete, because the UI is unwieldy.
Patches
The problem has been patched in plone.app.contenttypes.
- On Plone 6.2, upgrade to
plone.app.contenttypes5.0.1. - On Plone 6.1, upgrade to
plone.app.contenttypes4.0.10. - On Plone 6.0, upgrade to
plone.app.contenttypes3.0.12
Another part of this problem has been patched in plone.app.dexterity. See this advisory.
Workarounds
There are no known workarounds.
This problem was responsibly reported by Aldin Visnjic to the Plone/Zope Security Team. Thank you!
Note: The Plone/Zope Security team felt that the kind of fixes that were needed could be disruptive in corner cases if they were not careful. So they decided to develop the fixes publicly, giving the whole community the chance the review, and giving them the benefit from early feedback.
Which versions are affected by GHSA-8pcw-h6w9-h46g?
6 open source packages ship an affected version, including plone-app-contenttypes and plone.app.contenttypes.
| Package | Affected | Fixed in |
|---|---|---|
plone-app-contenttypes PyPI | All versions | 3.0.12 |
plone-app-contenttypes PyPI | From 4.0.0 | 4.0.10 |
plone-app-contenttypes PyPI | From 5.0.0 | 5.0.1 |
plone.app.contenttypes PyPI | All versions | 3.0.12 |
plone.app.contenttypes PyPI | From 4.0.0 | 4.0.10 |
plone.app.contenttypes PyPI | From 5.0.0 | 5.0.1 |
How do I fix GHSA-8pcw-h6w9-h46g?
Upgrade plone-app-contenttypes to a fixed version for your release line: 3.0.12, 4.0.10 or 5.0.1.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is GHSA-8pcw-h6w9-h46g being exploited?
There is no known exploitation of GHSA-8pcw-h6w9-h46g in the wild and no public exploit code.