What is CVE-2026-21915?

CVE-2026-21915 is a medium-severity vulnerability in Juniper Virtual Lightweight Collector, classified under CWE-183. CVSS score: 6.7/10. Published 2026-04-09.

How severe is CVE-2026-21915?

Medium severity. CVSS v3 base score is 6.7 out of 10.

RCE in Juniper Virtual Lightweight Collector

CVE-2026-21915

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.

EPSS: 0.022 (81.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.7 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.

Affected products

Juniper Virtual_lightweight_collector
Juniper Networks Jsi Lwc — versions 0

Weakness classification (CWE)

References

sirt@juniper.net (vendor-advisory, Vendor Advisory)

Frequently asked questions

What is CVE-2026-21915?: CVE-2026-21915 is a medium-severity vulnerability in Juniper Virtual Lightweight Collector, classified under CWE-183. CVSS score: 6.7/10. Published 2026-04-09.
How severe is CVE-2026-21915?: Medium severity. CVSS v3 base score is 6.7 out of 10.