CVE-2026-21902 Junos OS Evolved: PTX Series: A vulnerability allows a unauthenticated, network-based attacker to execute code as root
Unauthenticated remote attackers can execute code as root on Juniper PTX routers due to improper permission assignment in the anomaly detection framework.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-21902?
CVE-2026-21902 is a critical missing authorization vulnerability in Juniper Junos Os Evolved, published on 25 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-732
Which versions are affected by CVE-2026-21902?
It affects 1 product.
Products include Juniper Junos Os Evolved.
How do I fix CVE-2026-21902?
No fix has been published for CVE-2026-21902 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-21902 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-21902 exists.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in Juniper Junos Os Evolved
- CVE-2023-28983 Junos OS Evolved: Shell Injection vulnerability in the gNOI server
- CVE-2025-21599 Denial of service in Junos OS Evolved
- CVE-2024-47502 Junos OS Evolved: TCP session state is not always cleared on the Routing Engine leading to DoS
- CVE-2024-39531 Junos OS Evolved: ACX 7000 Series: Protocol specific DDoS configuration affects other protocols
- CVE-2024-39562 Junos OS Evolved: A high rate of SSH connections causes a Denial of Service
Sources
Also known as GHSA-5w57-gjvc-whwc.