Date: 
Wednesday, Apr 22nd, 2026
Advisory ID: 
BACKDROP-SA-CORE-2026-002
Security risk: 
Critical
Vulnerability: 
Cross Site Request Forgery
Versions affected: 
  • Backdrop Core 1.33.x versions prior to 1.33.2
  • Backdrop Core 1.32.x versions prior to 1.32.3
  • Backdrop versions 1.31 and prior do not receive security coverage.
Description: 

Backdrop's project installer does not check against a generated token before queuing projects to be downloaded from the Backdrop contrib repository. A user that has permission to post content could craft special tag to queue projects and download the projects. This vulnerability is mitigated by the fact that the user needs the ability to post HTML, and needs to get a privileged user to view the content they post. Additionally, there is no known way to enable projects, only download them.

Solution: 

Upgrade your site to the most recent version of Backdrop core. Download the latest release from the Backdrop CMS Releases or use the built-in updater to self-update. See the update instructions, if needed.

Reported By: 
  • Hammy
Fixed By: 
Coordinated By: 

Security email list

Backdrop maintains a security mailing list. Whenever a security release comes out, an email will be sent to everyone subscribed to that list, announcing the new release. Please follow the steps below to join the Security email list.

  1. Log in to backdropcms.org
  2. Edit your profile
  3. Switch to the "Subscriptions" tab
  4. Check the box labeled "Security updates"
  5. Save the form