CVE-2026-21915
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThe Juniper Networks Support Insights Virtual Lightweight Collector (vLWC) CLI suffers from improper input validation that allows shell command injection. A local attacker with high privileged access can inject shell commands through the CLI menu that execute with root privileges, achieving full system compromise.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 3.0.94CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- High
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify if Juniper vLWC is installedLocate the Virtual Lightweight Collector installation on the system - common paths include /opt/juniper/vlwc or check for the 'vlwc' binary in standard system binary directoriesAffected if The product is present on the system
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Determine the installed vLWC versionRun the version command for vLWC CLI (typically 'vlwc --version' or check version within the CLI interface)Affected if The installed version is lower than 3.0.94 (e.g., 3.0.x where x < 94, or any version in the 2.x line)
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Verify CLI interface accessibilityConfirm the vLWC CLI menu is accessible - check if the CLI binary exists and can be invokedAffected if The CLI is accessible and accepts user input
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Confirm high-privileged access existsDetermine if the attacker would have high-privileged access (root or administrative privileges) to the vLWC CLIAffected if High-privileged users can interact with the CLI menu
A system is affected if Juniper Virtual Lightweight Collector is installed with a version lower than 3.0.94 and the CLI interface is accessible to high-privileged users.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped3.0.94
Upgrade Juniper vLWC to version 3.0.94 or later to obtain the patched CLI input validation.
3.0.94 or later
- Obtain Virtual Lightweight Collector version 3.0.94 or later from Juniper Networks official sources
- Review the upgrade documentation on kb.juniper.net for the specific upgrade procedure
- Execute the upgrade following Juniper's standard vLWC upgrade process
- Verify the upgrade was successful by checking the installed version
- Confirm the CLI command injection vulnerability is remediated
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-21915 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-21915 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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