CVE-2026-25903
MEDIUMApache NiFi 1.1.0 through 2.7.2 are missing authorization when updating configuration properties on extension components that have specific Required Permissions based on the Restricted…
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Description
Apache NiFi 1.1.0 through 2.7.2 are missing authorization when updating configuration properties on extension components that have specific Required Permissions based on the Restricted annotation. The Restricted annotation indicates additional privileges required to add the annotated component to the flow configuration, but framework authorization did not check restricted status when updating a component previously added. The missing authorization requires a more privileged user to add a restricted component to the flow configuration, but permits a less privileged user to make property configuration changes. Apache NiFi installations that do not implement different levels of authorization for Restricted components are not subject to this vulnerability because the framework enforces write permissions as the security boundary. Upgrading to Apache NiFi 2.8.0 is the recommended mitigation.
Affected Products
nifiapacheDetection & mitigation playbook
Vendor / applianceDetect
Inventory every apache nifi deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for exploitation at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Fix
Apply the apache nifi security patch or hotfix for CVE-2026-25903 on the affected version, following the vendor advisory for your exact build.
Workarounds
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2026-25903 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.
Tailored to CVE-2026-25903. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-25903 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2026-25903 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.