CVE-2026-21915 JSI Virtual Lightweight Collector: Shell escape allows privilege escalation to root
A local high-privileged attacker can inject shell commands via the CLI to escalate privileges to root on Juniper JSI vLWC.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-21915?
CVE-2026-21915 is a high-severity command injection vulnerability in Juniper Networks JSI LWC, published on 9 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2026-21915?
It affects 1 product.
Products include Juniper Virtual Lightweight Collector.
How do I fix CVE-2026-21915?
No fix has been published for CVE-2026-21915 yet. Limit exposure of the affected software until one is available.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2026-21915 being exploited?
There is no known exploitation of CVE-2026-21915 in the wild and no public exploit code.
Other vulnerabilities in Juniper Networks JSI LWC
Sources
Also known as GHSA-r893-59mm-pxrg.