Juniper JSI vLWC CLI Shell Cmd Injection (3.0.93)
CVE-2026-21915 Published on April 9, 2026
JSI Virtual Lightweight Collector: Shell escape allows privilege escalation to root
A Permissive List of Allowed Input vulnerability in the CLI of Juniper Networks Support Insights (JSI) Virtual Lightweight Collector (vLWC) allows a local, high privileged attacker to escalate their privileges to root.
The CLI menu accepts input without carefully validating it, which allows for shell command injection. These shell commands are executed with root permissions and can be used to gain complete control of the system.
This issue affects all JSI vLWC versions before 3.0.94.
Vulnerability Analysis
CVE-2026-21915 can be exploited with local system access, and requires user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to be very high.
Weakness Type
What is an Allowlist / Allow List Vulnerability?
The product implements a protection mechanism that relies on a list of inputs (or properties of inputs) that are explicitly allowed by policy because the inputs are assumed to be safe, but the list is too permissive - that is, it allows an input that is unsafe, leading to resultant weaknesses.
CVE-2026-21915 has been classified to as an Allowlist / Allow List vulnerability or weakness.
Affected Versions
Juniper Networks JSI LWC:- Before 3.0.94 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.