CVE-2026-56721 CamaleonCMS 2.9.2 Privilege Escalation via Parameter Confusion in UsersController
Authenticated low-privileged users can escalate privileges and take over the site by exploiting parameter confusion to overwrite administrator credentials.
- 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-2026-56721?
CVE-2026-56721 is a high-severity vulnerability in owen2345 CamaleonCMS, published on 11 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
CamaleonCMS version 2.9.2 and earlier contains a privilege escalation vulnerability via insecure direct object reference (IDOR) that allows authenticated low-privileged attackers to overwrite any user's credentials by exploiting a parameter confusion flaw between the authorization filter and action body in the UsersController. Attackers can send a PATCH request to the updated_ajax endpoint setting params[:id] to their own user ID to pass the self-authorization check while simultaneously setting params[:user_id] to a victim's ID, causing the controller to load and mutate the victim's account, including overwriting administrator passwords to achieve full site takeover.
Weakness: CWE-639
Which versions are affected by CVE-2026-56721?
How do I fix CVE-2026-56721?
No fix has been published for CVE-2026-56721 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-56721 being exploited?
There is no known exploitation of CVE-2026-56721 in the wild and no public exploit code.
Sources
Also known as GHSA-m39h-f7fw-54qw.