Medium 4.4Known exploited (CISA KEV)Published Mar 12, 2025

CVE-2025-21590Junos OS: An local attacker with shell access can execute arbitrary code

Updated under an hour ago (2026-10-19 10:00 UTC)

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It affects Juniper Networks Junos OS and 1 other product. Add what you run to find out whether that includes you.

CISA lists it as known exploited since Mar 13, 2025; federal agencies had to remediate by Apr 3, 2025. Treat that date as your deadline.

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Every CVE for Juniper Networks Junos OS

Exploited in the last 30 days

An Improper Isolation or Compartmentalization vulnerability in the kernel of Juniper Networks Junos OS allows a local attacker with high privileges to compromise the integrity of the device. A local attacker with access to the shell is able to inject arbitrary code which can compromise an affected device. This issue is not exploitable from the Junos CLI. This issue affects Junos OS: * All versions before 21.2R3-S9, * 21.4 versions before 21.4R3-S10, * 22.2 versions before 22.2R3-S6, * 22.4 versions before 22.4R3-S6, * 23.2 versions before 23.2R2-S3, * 23.4 versions before 23.4R2-S4, * 24.2 versions before 24.2R1-S2, 24.2R2.

CVSS: 4.4 MEDIUM (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N
Weakness (CWE): CWE-653
Known exploited: Added to CISA KEV Mar 13, 2025; federal remediation due Apr 3, 2025Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
EPSS (exploitation in the next 30 days): 1.74% (percentile 77)
Assigned by: juniper
NVD analysis: Analyzed
Record last updated: Feb 26, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Juniper Networks Junos OS juniper_networks:junos_os (from the name)	before 21.2R3-S9; from 21.4 before 21.4R3-S10; from 22.2 before 22.2R3-S6; from 22.4 before 22.4R3-S6; from 23.2 before 23.2R2-S3; from 23.4 before 23.4R2-S4; from 24.2 before 24.2R1-S2, 24.2R2	CNA record
juniper junos juniper:junos	before 21.2; 21.2; 21.2; 21.2; 21.2; 21.2; 21.2; 21.2; and 71 more ranges	NVD

References

https://supportportal.juniper.net/JSA93446vendor-advisory
https://cloud.google.com/blog/topics/threat-intelligence/china-nexus-espionage-targets-juniper-routersthird-party-advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-21590us-government-resource

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.