Juniper JSI LWC up to 3.0.93 Virtual Lightweight Collector permissive list of allowed inputs

Summaryinfo

A vulnerability marked as critical has been reported in Juniper JSI LWC up to 3.0.93. Affected is an unknown function of the component Virtual Lightweight Collector. This manipulation causes permissive list of allowed inputs. This vulnerability appears as CVE-2026-21915. The attack requires local access. There is no available exploit. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Juniper JSI LWC up to 3.0.93 and classified as critical. Affected by this vulnerability is an unknown code of the component Virtual Lightweight Collector. The manipulation with an unknown input leads to a permissive list of allowed inputs vulnerability. The CWE definition for the vulnerability is CWE-183. 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. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at kb.juniper.net. This vulnerability is known as CVE-2026-21915 since 01/05/2026. The exploitation appears to be easy. An attack has to be approached locally. Additional levels of successful authentication are necessary for exploitation. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 04/10/2026).

Upgrading to version 3.0.94 eliminates this vulnerability.

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Productinfo

Vendor

• Juniper

Name

• JSI LWC

Version

• 3.0.0
• 3.0.1
• 3.0.2
• 3.0.3
• 3.0.4
• 3.0.5
• 3.0.6
• 3.0.7
• 3.0.8
• 3.0.9
• 3.0.10
• 3.0.11
• 3.0.12
• 3.0.13
• 3.0.14
• 3.0.15
• 3.0.16
• 3.0.17
• 3.0.18
• 3.0.19
• 3.0.20
• 3.0.21
• 3.0.22
• 3.0.23
• 3.0.24
• 3.0.25
• 3.0.26
• 3.0.27
• 3.0.28
• 3.0.29
• 3.0.30
• 3.0.31
• 3.0.32
• 3.0.33
• 3.0.34
• 3.0.35
• 3.0.36
• 3.0.37
• 3.0.38
• 3.0.39
• 3.0.40
• 3.0.41
• 3.0.42
• 3.0.43
• 3.0.44
• 3.0.45
• 3.0.46
• 3.0.47
• 3.0.48
• 3.0.49
• 3.0.50
• 3.0.51
• 3.0.52
• 3.0.53
• 3.0.54
• 3.0.55
• 3.0.56
• 3.0.57
• 3.0.58
• 3.0.59
• 3.0.60
• 3.0.61
• 3.0.62
• 3.0.63
• 3.0.64
• 3.0.65
• 3.0.66
• 3.0.67
• 3.0.68
• 3.0.69
• 3.0.70
• 3.0.71
• 3.0.72
• 3.0.73
• 3.0.74
• 3.0.75
• 3.0.76
• 3.0.77
• 3.0.78
• 3.0.79
• 3.0.80
• 3.0.81
• 3.0.82
• 3.0.83
• 3.0.84
• 3.0.85
• 3.0.86
• 3.0.87
• 3.0.88
• 3.0.89
• 3.0.90
• 3.0.91
• 3.0.92
• 3.0.93

License

• commercial

Website

• Vendor: https://www.juniper.net/

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Entryinfo

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