How severe is CVE-2026-21915?

CVE-2026-21915 has a CVSS 3.x base score of 6.7, rated medium severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-21915 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-21915?

CVE-2026-21915 affects Juniper Virtual Lightweight Collector. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-21915?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-21915 have an EU (EUVD) identifier?

Yes. CVE-2026-21915 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-21078.

When was CVE-2026-21915 published?

CVE-2026-21915 was published on 2026-04-09 and last updated on 2026-07-08.

CVE-2026-21915

CVE-2026-21915 is a medium-severity vulnerability in Juniper Virtual Lightweight Collector with a CVSS 3.x base score of 6.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-78.

Key facts

Severity: Medium (CVSS 3.x base score 6.7)
CVSS v4: 8.4
EPSS exploit prediction: 2% (81st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-21078
Weakness: CWE-78
Affected product: Juniper Virtual Lightweight Collector
Published: 2026-04-09
Last modified: 2026-07-08

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.

Frequently asked questions

What is 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.
How severe is CVE-2026-21915?: CVE-2026-21915 has a CVSS 3.x base score of 6.7, rated medium severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-21915 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-21915?: CVE-2026-21915 affects Juniper Virtual Lightweight Collector. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-21915?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-21915 have an EU (EUVD) identifier?: Yes. CVE-2026-21915 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-21078.
When was CVE-2026-21915 published?: CVE-2026-21915 was published on 2026-04-09 and last updated on 2026-07-08.

References

https://kb.juniper.net/JSA106016

Affected products (1)

cpe:2.3:a:juniper:virtual_lightweight_collector:*:*:*:*:*:*:*:*

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