What’s Vulnerable › Vulnerabilities

CVE-2026-56721: CamaleonCMS 2.9.2 Privilege Escalation via Parameter Confusion in UsersController

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-11 · updated 2026-10-24
• Weakness: CWE-639

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.

Affected products

• owen2345 CamaleonCMS: through 2.9.2

References

• https://github.com/owen2345/camaleon-cms
• https://github.com/owen2345/camaleon-cms/commit/26345034523a505cb01615509b7f0a665e89ae3e
• https://github.com/owen2345/camaleon-cms/pull/1185
• https://www.vulncheck.com/advisories/camaleoncms-privilege-escalation-via-parameter-confusion-in-userscontroller

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