# CVE-2026-33784: Juniper Networks JSI vLWC use of default password

Source: https://junglewise.ai/threats/cve-2026-33784-juniper-networks-jsi-vlwc-use-of-default-password  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-09. Updated: 2026-07-08  
License: CC BY 4.0 with a link back

CVE-2026-33784 · Severity: critical · CVSS 9.8 · Published 2026-04-09

Juniper Networks Support Insights (JSI) Virtual Lightweight Collector (vLWC) is a tool used to collect and transmit diagnostic data from network devices. A security flaw exists where these systems ship with a default password for a high-privileged account that is not required to be changed during setup. An unauthorized person could use this known password over the network to gain full control of the device, potentially leading to data theft or disruption of network monitoring services.

Vendors: [Juniper](https://junglewise.ai/threats/vendors/juniper), [Juniper Networks](https://junglewise.ai/threats/vendors/juniper-networks).

## Quick answers

**Is CVE-2026-33784 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-33784 being exploited in the wild.

**How severe is CVE-2026-33784?** Critical severity, with a CVSS score of 9.8, published 9 April 2026.

**Which products and versions are affected?** Juniper Networks Support Insights (JSI) Virtual Lightweight Collector (vLWC) All versions before 3.0.94.

**Is there a fix for CVE-2026-33784?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-33784 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-33784?** Check whether you run Juniper Virtual Lightweight Collector or Juniper Networks Support Insights Virtual Lightweight Collector. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A Use of Default Password vulnerability (CWE-1393) exists in the Juniper Networks Support Insights (JSI) Virtual Lightweight Collector (vLWC). The software images ship with a pre-configured initial password for a high-privileged account, and the provisioning process does not enforce a password change. An unauthenticated attacker with network access to the vLWC can use these default credentials to gain full administrative access to the system. This issue affects all versions of vLWC prior to 3.0.94. Users are advised to upgrade to version 3.0.94 or later to remediate the vulnerability.

## Affected products

- Juniper Networks Support Insights (JSI) Virtual Lightweight Collector (vLWC) All versions before 3.0.94

## Timeline

- 2026-04-09: advisory: Initial advisory published by Juniper Networks

## References

- [https://kb.juniper.net/JSA107871](https://kb.juniper.net/JSA107871)

## Related threats

- [Juniper Networks JSI vLWC privilege escalation in CLI](https://junglewise.ai/threats/cve-2026-21915-juniper-networks-jsi-vlwc-privilege-escalation-in-cli)