Executive brief
CKAN, an open-source data portal platform, contains a vulnerability where security protections against Cross-Site Request Forgery (CSRF) can be accidentally disabled. An attacker can trigger this by sending a specific unauthenticated request, which causes the server to stop verifying the legitimacy of subsequent requests for that session. If exploited, an attacker could trick a logged-in user into performing unintended actions, such as deleting data or changing settings, without their knowledge.
Technical details
A Cross-Site Request Forgery (CSRF) vulnerability exists in CKAN due to improper state management in the flask-wtf.csrf.CSRFProtect() middleware. When an endpoint is accessed via an unauthenticated request or a request using tokens, the middleware incorrectly marks the view as exempt from CSRF protection. This exemption is stored in a module-level variable within the flask_app middleware, causing the exemption to persist for the entire life of the server process (e.g., a uwsgi worker). An attacker can 'prime' a worker by sending an anonymous request to a protected endpoint, subsequently allowing them to bypass CSRF protections for authenticated users handled by that same worker. This can be combined with XSS or social engineering to execute unauthorized actions using a victim's credentials. The issue is fixed in versions 2.10.10 and 2.11.5.
Affected products
- ckan ckan >= 2.10.0, < 2.10.10; >= 2.11.0, <= 2.11.4
Timeline
- 2026-04-29: disclosed
- 2026-04-29: advisory
- 2026-04-29: patched