CVE-2026-84115

Name of the Vulnerable Software and Affected Versions Cleo Harmony versions 5.8.1.0 through 5.8.1.10

Description An issue exists in the JWT (JSON Web Token) refresh token handler within the /api/connections endpoint. A remote attacker can manipulate the Bearer argument in HTTP headers to bypass authorization controls and achieve improper privilege management, potentially escalating their privileges to administrative levels. This flaw allows unauthorized access to protected functionality and integrated external systems. The vulnerability has been reproduced by researchers, and an exploit is publicly available.

Recommendations Upgrade Cleo Harmony to version 5.8.1.11. Restrict access to the /api/connections endpoint to trusted networks to minimize the risk of exploitation.