CVE-2026-33791 PUBLISHED

Junos OS and Junos OS Evolved: Execution of crafted CLI commands allows for arbitrary shell injection as root

Assigner: juniper
Reserved: 23.03.2026 Published: 09.04.2026 Updated: 09.04.2026

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.

Metrics

CVSS Vector: 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
CVSS Score: 8.4

Product Status

Vendor Juniper Networks
Product Junos OS
Versions Default: unaffected
  • affected from 0 to 22.4R3-S8 (excl.)
  • affected from 23.2 to 23.2R2-S5 (excl.)
  • affected from 23.4 to 23.4R2-S7 (excl.)
  • affected from 24.2 to 24.2R2-S2 (excl.)
  • affected from 24.4 to 24.4R2 (excl.)
  • affected from 25.2 to 25.2R2 (excl.)
Vendor Juniper Networks
Product Junos OS Evolved
Versions Default: unaffected
  • affected from 0 to 22.4R3-S8-EVO (excl.)
  • affected from 23.2 to 23.2R2-S5-EVO (excl.)
  • affected from 23.4 to 23.4R2-S7-EVO (excl.)
  • affected from 24.2 to 24.2R2-S2-EVO (excl.)
  • affected from 24.4 to 24.4R2-EVO (excl.)
  • affected from 25.2 to 25.2R1-S1-EVO, 25.2R2-EVO (excl.)

Exploits

Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

Workarounds

One of the following mitigations will reduce the risk of malicious exploitation: * Use access lists or firewall filters to limit access to the CLI only from trusted hosts and administrators. * Avoid configuring access to any part of the 'set system'​ stanza for non-privileged users.

Solutions

The following software releases have been updated to resolve this specific issue: Junos OS 22.4R3-S8, 23.2R2-S5, 23.4R2-S7, 24.2R2-S2, 24.4R2, 25.2R2, 25.4R1, and all subsequent releases.

Junos OS Evolved 22.4R3-S8-EVO, 23.2R2-S5-EVO, 23.4R2-S7-EVO, 24.2R2-S2-EVO, 24.4R2-EVO, 25.2R1-S1-EVO, 25.2R2-EVO, 25.4R1-EVO, and all subsequent releases.

References

Problem Types

  • CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') CWE