CVE-2026-39940 ChurchCRM has an Open Redirect via the ‘linkBack’ URL Parameter in DonatedItemEditor.php
An attacker can trick authenticated users into visiting malicious URLs via the linkBack parameter, potentially leading to phishing or credential theft.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-39940?
CVE-2026-39940 is a medium-severity vulnerability in ChurchCRM CRM, published on 13 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
ChurchCRM is an open-source church management system. Prior to 7.0.0, it was possible in many places across the ChurchCRM application to create a link that, when visited by an authenticated user, would redirect them to any URL chosen by an attacker if they clicked 'Cancel' button on the page. For this write-up the DonatedItemEditor.php will be used as an example, however wherever all instances of 'linkBack' should be assessed. This vulnerability is fixed in 7.0.0.
Weakness: CWE-601
Which versions are affected by CVE-2026-39940?
How do I fix CVE-2026-39940?
No fix has been published for CVE-2026-39940 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-39940 being exploited?
There is no known exploitation of CVE-2026-39940 in the wild and no public exploit code.
Sources
Also known as CVE-2026-35578.