Juniper Junos OS fixes a high-severity vulnerability

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[TLP:CLEAR] Juniper Junos OS fixes a high-severity vulnerability

Juniper Networks fixes a high-severity vulnerability in Junos OS Evolved [1]. Fixed product versions: 25.4R1-S1-EVO, 25.4R2-EVO (future release), 26.2R1-EVO (future release).

Juniper Networks Junos OS - RCE (CVE-2026-21902)

CVSS 9.3 (Critical)

Because the network anomaly detection service is reachable from an external network interface, an unauthenticated remote attacker can execute code with root privileges, which may lead to complete takeover of the device. This service is enabled by default [1].

The vulnerability is present in product:

Junos OS Evolved; >=25.4R1-EVO, <25.4R1-S1-EVO; >25.4R1-S1-EVO, <25.4R2-EVO;

CVSS: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:L/AU:Y/R:U/RE:M/U:Red

More information:

CVE-2026-21902 at cve.org, NVD
CWE-732: Incorrect Permission Assignment for Critical Resource at cwe.mitre.org

The vulnerability was publicly disclosed 25. 2. 2026.

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[TLP:CLEAR] Juniper Junos OS fixes a high-severity vulnerability

Juniper Networks Junos OS - RCE (CVE-2026-21902)

CVSS 9.3 (Critical)

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