CVE-2026-21916

moderate-risk

Published 2026-04-09

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.

Do I need to act?

0.01% chance of exploitation

EPSS score — low exploit probability

Not on CISA KEV list

No confirmed active exploitation reported to CISA

Patch status unknown

Check vendor advisories for fix availability and mitigation guidance

CVSS 7.3/10 High

LOCAL / LOW complexity

Affected Products (20)

Junos

Affected Vendors

Juniper

References (1)

Mitigation https://kb.juniper.net/JSA107807

/ 100

moderate-risk

Severity 23/34 · High

Exploitability 0/34 · Minimal

Exposure 24/34 · High