CVE-2026-21902: exploitation status and patch state

CVE-2026-21902 · CVSS 9.8 CRITICAL · EPSS 18%

An Incorrect Permission Assignment for Critical Resource vulnerability in the On-Box Anomaly detection framework of Juniper Networks Junos OS Evolved on PTX Series allows an unauthenticated, network-based attacker to execute code as root. The On-Box Anomaly detection framework should only be reachable by other internal processes over the internal routing instance, but not over an externally exposed port. With the ability to access and manipulate the service to execute code as root a remote attacker can take complete control of the device. Please note that this service is enabled by default as no specific configuration is required. This issue affects Junos OS Evolved on PTX Series: * 25.4 versions before 25.4R1-S1-EVO, 25.4R2-EVO. This issue does not affect Junos OS Evolved versions before 25.4R1-EVO. This issue does not affect Junos OS.

Is CVE-2026-21902 exploited?

Which products and versions are affected?

No affected package list recorded here yet.

Is there a patch?

No patch identifier recorded here yet.

What PlainSec published about CVE-2026-21902

PlainSec has not published a story about this CVE.

Primary sources

What this record does not say

KEV and EPSS are re-checked daily. Record last updated 2026-08-11.