CVE-2026-21916: Juniper Junos

High severity, CVSS 7.3. EPSS: 0.1% chance of exploitation in the next 30 days.

A UNIX Symbolic Link (Symlink) Following vulnerability in the CLI of Juniper Networks Junos OS allows a local, authenticated attacker with low privileges to escalate their privileges to root which will lead to a complete compromise of the system. When after a user has performed a specific 'file link ...' CLI operation, another user commits (unrelated configuration changes), the first user can login as root. This issue affects Junos OS: * all versions before 23.2R2-S7, * 23.4 versions before 23.4R2-S6, * 24.2 versions before 24.2R2-S3, * 24.4 versions before 24.4R2-S2, * 25.2 versions before 25.2R2. This issue does not affect versions 25.4R1 or later.

Affected products

• Juniper Junos: before 23.2 (fixed in 23.2); version 23.2 only; version 23.4 only; version 24.2 only; version 24.4 only; version 25.2 only

Published 2026-04-09. Last modified 2026-06-17.