JunosOperating system · Juniper

CVE-2026-33791

MEDIUM · 6.7 CVSS v3.1 Published 2026-04-09
Fix available
A fix is available. Upgrade to 22.4 or later.
See remediation →
69/100
Remediation priority · Elevated
Zero-click

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 · unedited
An OS Command Injection vulnerability in the CLI processing of Juniper Networks Junos OS and Junos OS Evolved allows a local, high-privileged attacker executing specific, crafted CLI commands to inject arbitrary shell commands as root, leading to a complete compromise of the system. Certain 'set system' commands, when executed with crafted arguments, are not properly sanitized, allowing for arbitrary shell injection. These shell commands are executed as root, potentially allowing for complete control of the vulnerable system. This issue affects: Junos OS:  * all versions before 22.4R3-S8,  * from 23.2 before 23.2R2-S5,  * from 23.4 before 23.4R2-S7,  * from 24.2 before 24.2R2-S2,  * from 24.4 before 24.4R2,  * from 25.2 before 25.2R2;  Junos OS Evolved:  * all versions before 22.4R3-S8-EVO,  * from 23.2 before 23.2R2-S5-EVO,  * from 23.4 before 23.4R2-S7-EVO,  * from 24.2 before 24.2R2-S2-EVO,  * from 24.4 before 24.4R2-EVO,  * from 25.2 before 25.2R1-S1-EVO, 25.2R2-EVO.

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 confidence

OS Command Injection vulnerability in Juniper Junos OS and Junos OS Evolved CLI processing. A local, high-privileged attacker can execute crafted 'set system' CLI commands with malicious arguments that are not properly sanitized, allowing arbitrary shell command execution as root and complete system compromise.

MitigationApply vendor-provided patches by upgrading to the specific fixed versions (22.4R3-S8, 23.2R2-S5, 23.4R2-S7, 24.2R2-S2, 24.4R2, 25.2R2 or later depending on branch). Limit CLI access to trusted, high-privilege administrators only.

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
JunosOperating system
Affected:< 22.4= 22.4= 23.2= 23.4= 24.2= 24.4= 25.2
Junos Os EvolvedOperating system
Affected:< 22.4= 22.4= 23.2= 23.4= 24.2= 24.4= 25.2

CVSS 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 checks

Work through these to decide whether this CVE applies to you.

  1. Determine installed Junos version
    Run the command 'show version' or 'show version detail' from the CLI (or 'show version extensive' on Junos OS Evolved) to obtain the exact software version number
    Affected if The displayed version matches < 22.4; = 22.4; = 23.2; = 23.4; = 24.2; = 24.4; or = 25.2
  2. Confirm product type
    Identify whether the device runs Junos OS or Junos OS Evolved using the output from the version command (Junos OS Evolved typically shows 'Junos OS Evolved' in the hostname or version details)
    Affected if Either Junos OS or Junos OS Evolved is running with a vulnerable version from step 1
  3. Verify CLI access exists
    Confirm that CLI (command-line interface) access is enabled and accessible. Check for presence of 'set system services ssh' or 'set system services telnet' in the configuration by running 'show configuration | display set | match services'
    Affected if CLI access services are configured and available, making the attack surface viable for a local high-privileged attacker

A device is affected if it runs Junos OS or Junos OS Evolved with a version matching the listed vulnerable versions and has CLI access configured for local high-privileged users.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Upgrade available Upgrade to 22.4 or later
Fixed in 22.4
Interim mitigation

Apply vendor-provided patches by upgrading to the specific fixed versions (22.4R3-S8, 23.2R2-S5, 23.4R2-S7, 24.2R2-S2, 24.4R2, 25.2R2 or later depending on branch). Limit CLI access to trusted, high-privilege administrators only.

Recommended fix High confidence

22.4R3-S8 or later for 22.4 branch; 23.2R2-S5 or later for 23.2 branch; 23.4R2-S7 or later for 23.4 branch; 24.2R2-S2 or later for 24.2 branch; 24.4R2 or later for 24.4 branch; 25.2R2 or later for 25.2 branch (use EVO variants for Junos OS Evolved)

  1. 1. Identify the current Junos OS or Junos OS Evolved version running on the device using 'show version'
  2. 2. Determine which branch you are on (22.4, 23.2, 23.4, 24.2, 24.4, or 25.2)
  3. 3. For Junos OS 22.4 branch: upgrade to 22.4R3-S8 or later
  4. 4. For Junos OS 23.2 branch: upgrade to 23.2R2-S5 or later
  5. 5. For Junos OS 23.4 branch: upgrade to 23.4R2-S7 or later
  6. 6. For Junos OS 24.2 branch: upgrade to 24.2R2-S2 or later
  7. 7. For Junos OS 24.4 branch: upgrade to 24.4R2 or later
  8. 8. For Junos OS 25.2 branch: upgrade to 25.2R2 or later
Caveat Review Junos OS release notes for any behavior changes between your current version and target version before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Junos Scoped from the published advisory
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing8.0 h
  • Review / QA4.0 h
30.0 hours of engineering $5,280
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-33791 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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