Apache NiFi Vulnerability (CVE-2026-25903) Exposes Systems to Authorization Bypass A high-severity vulnerability in Apache NiFi, tracked as CVE-2026-25903, allows lower-privileged users to bypass authorization controls and modify restricted components. The flaw affects versions 1.1.0 through 2.7.2 and was patched in version 2.8.0. The issue stems from missing authorization checks when updating configuration properties of extension components marked as Restricted. While these components require elevated privileges to be added to a data flow, the vulnerability enables less privileged users to alter their configurations post-deployment, circumventing intended security controls. Exploitation could allow attackers to tamper with data flow logic, execute unauthorized system commands, or manipulate sensitive processing operations posing significant risks for organizations handling regulated or confidential data streams. The vulnerability was responsibly disclosed by David Handermann and rated High severity by Apache’s Project Management Committee. Apache NiFi, a widely used platform for data flow automation, is particularly critical in environments where restricted components manage sensitive workflows. The risk of exploitation depends on how authorization policies are implemented; systems with granular privilege separation face lower exposure. Apache has urged users to upgrade to NiFi 2.8.0 or later to mitigate the flaw and emphasized responsible disclosure through its security mailing list. Technical details remain restricted until remediation is widely adopted.