All vulnerabilities
CVE-2026-21902

Junos OS Evolved: PTX Series: A vulnerability allows a unauthenticated, network-based attacker to execute code as root

Juniper Networks Junos OS EvolvedNetwork & edge
Open in ThreatlineRecord JSON
CVSS
9.8Critical
ExploitationPublic exploit codeCISA's assessment says proof of concept code is public, assessed 25 Feb 2026. Not in the KEV catalogCISA via CVE List
Exploit odds (EPSS)18.5%Chance of exploitation activity in the next 30 days, higher than 97% of CVEs. Scored 26 Oct 2026FIRST EPSS
Fixed in25.4R1-S1-EVO, 25.4R2-EVOFixed versionCVE List
Published25 Feb 2026Updated 4 Mar 2026CVE List

What fixes it

  • 25.4R1-S1-EVO, 25.4R2-EVOJunos OS EvolvedCVE List

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Timeline

  1. 25 Feb 2026, 16:59 UTCPublishedCVE List
  2. 26 Oct 2026, 14:53 UTCExploit code publicGitHub proof-of-concept repositories

Reports 1

1 outlet mention it. Reports are not confirmation; each links to its source.

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.

Text from CVE List

Affected versions 2

  • Junos OS Evolvedaffected: 25.4 before 25.4R1-S1-EVO, 25.4R2-EVOCVE List
  • Junos OS Evolvedunaffected: all versions before 25.4R1-EVOCVE List

References 3