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Response snapshot Oct 27, 2026, 07:39 UTC

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VulnerabilityCVE-2026-33791

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...

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.

At a glance

Exploited
Not known
Severity
8.4 High (CVSS 4.0)
Chance of exploitation
0.7% in the next 30 days
Sources
2 independent sources

What to do

Check the vendor advisory for affected versions and fixes.

Read NVD CVE-2026-33791 (opens a new tab)

What happened

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;

Continue reading

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.

Scores and how they were measured

CVSS base severity

8.4

Version 4.0As of

CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:A/V:C/RE:M/U:Amber

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

0.7%

Scored Percentile 52.6%

Model and measurement source (opens a new tab)

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    NVD CVE-2026-33791 (opens a new tab)

    NVD record: description, CVSS (the CNA score is preferred), affected products, and publication date. Not evidence of exploitation.

    Published Checked

  2. Primary source

    Vendor advisory (via NVD references) (opens a new tab)

    The vendor advisory referenced by the CVE record, for affected versions and fixes.

    Published Date not suppliedChecked

  3. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  4. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  5. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  6. Primary source

    FIRST measured EPSS score (opens a new tab)

    Measured EPSS probability and percentile for CVE-2026-33791, scored 2026-10-26. This is a model estimate, not proof of exposure.

    Published Checked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, October 26). 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... (CVE-2026-33791). https://kevwire.com/record/CVE-2026-33791

MLA

"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... (CVE-2026-33791)." KEVWire, 26 Oct. 2026, kevwire.com/record/CVE-2026-33791.

Chicago

KEVWire. "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... (CVE-2026-33791)." Last modified October 26, 2026. https://kevwire.com/record/CVE-2026-33791.

Evidence summary (plain text)

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... (Apr 9, 2026).
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.
CVSS 8.4 (version 4.0; evidence as of Oct 26, 2026; https://nvd.nist.gov/vuln/detail/CVE-2026-33791).
EPSS 0.7% for the following 30 days, scored Oct 26, 2026 (https://api.first.org/data/v1/epss?cve=CVE-2026-33791&date=2026-10-26).
Sources:
NVD CVE-2026-33791: https://nvd.nist.gov/vuln/detail/CVE-2026-33791
Vendor advisory (via NVD references): https://kb.juniper.net/JSA107875
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-26T21:46:18.206Z&lastModEndDate=2026-10-26T23:15:56.398Z&resultsPerPage=500&startIndex=0
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-26T21:12:32.956Z&lastModEndDate=2026-10-26T22:45:54.988Z&resultsPerPage=500&startIndex=0
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-26T20:37:18.143Z&lastModEndDate=2026-10-26T22:10:56.995Z&resultsPerPage=500&startIndex=500
FIRST measured EPSS score: https://api.first.org/data/v1/epss?cve=CVE-2026-33791&date=2026-10-26
Record ID: CVE-2026-33791.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Oct 27, 2026, 01:40 UTC. Ingestion is not an independent editorial investigation.

NVD status: Modified. Publication in the NVD is not evidence of exploitation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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Record details

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