# CVE-2026-33791: Junos OS and Junos OS Evolved: Execution of crafted CLI commands allows for arbitrary shell injection as root

> A local high-privileged attacker can inject arbitrary shell commands as root via crafted CLI commands, leading to complete system compromise.

- **Severity:** High 8.4 (`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/AU:Y/R:A/V:C/RE:M/U:Amber`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 9 Apr 2026
- **Updated:** 22 Apr 2026
- **Also known as:** GHSA-j4rr-c2v3-296r

## What is CVE-2026-33791?

CVE-2026-33791 is a high-severity command injection vulnerability in Juniper Junos, published on 9 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2026-33791?

It affects 2 products.


Products: Juniper Junos, Juniper Junos Os Evolved.

## How do I fix CVE-2026-33791?

No fix has been published for CVE-2026-33791 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-33791 being exploited?

There is no known exploitation of CVE-2026-33791 in the wild and no public exploit code.

## Other vulnerabilities in Juniper Junos

- [CVE-2023-36845](https://insights.sbomify.com/CVE-2023-36845/): Juniper Junos OS EX Series and SRX Series PHP External Variable Modification (critical 9.8, exploited in the wild)
- [CVE-2020-1631](https://insights.sbomify.com/CVE-2020-1631/): Juniper Junos OS Path Traversal (high 8.8, exploited in the wild)
- [CVE-2025-21590](https://insights.sbomify.com/CVE-2025-21590/): Juniper Junos OS Improper Isolation or Compartmentalization (medium 6.7, exploited in the wild)
- [CVE-2023-36851](https://insights.sbomify.com/CVE-2023-36851/): Juniper Junos OS SRX Series Missing Authentication for Critical Function (medium 5.3, exploited in the wild)
- [CVE-2023-36844](https://insights.sbomify.com/CVE-2023-36844/): Juniper Junos OS EX Series PHP External Variable Modification (medium 5.3, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-33791 and fix it if it is affected.

What it is: CVE-2026-33791 is a high-severity command injection vulnerability in Juniper Junos, published on 9 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-33791 in the wild and no public exploit code.

Affected product: Juniper Junos. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-33791/ (Markdown: https://insights.sbomify.com/CVE-2026-33791/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33791
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33791
- OSV: https://osv.dev/vulnerability/CVE-2026-33791

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33791/
Summaries are generated and may contain mistakes; the official description above is the record.