CVE-2025-21590Known exploitation

Code execution via trusted-process memory injection

Published Mar 12, 2025 · Updated Feb 26, 2026

Improper isolation in the Juniper Networks Junos OS kernel allows local users with high privileges to inject arbitrary code. The kernel permits shell-level process-memory injection into legitimate processes, bypassing veriexec enforcement against untrusted binaries. Exploitation requires high-privileged shell access, does not work from the Junos CLI, and compromises device integrity without reported confidentiality or availability impact.

CVSS severity6.7
Medium
EPSS probability1.71%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper isolation in the Juniper Networks Junos OS kernel allows local users with high privileges to inject arbitrary code. The kernel permits shell-level process-memory injection into legitimate processes, bypassing veriexec enforcement against untrusted binaries. Exploitation requires high-privileged shell access, does not work from the Junos CLI, and compromises device integrity without reported confidentiality or availability impact.

The record

CVE
CVE-2025-21590
Published
Mar 12, 2025
Updated
Feb 26, 2026
Vendor
Juniper Networks
Product
Junos OS
Classifications
CWE-653, T1055
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Mar 12, 2025CVE publishedPublication date reported by the CVE source.
  2. Feb 26, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <21.2R3-S9
  2. Affected versionversion=21.4 <21.4R3-S10
  3. Affected versionversion=22.2 <22.2R3-S6
  4. Affected versionversion=22.4 <22.4R3-S6
  5. Affected versionversion=23.2 <23.2R2-S3
  6. Affected versionversion=23.4 <23.4R2-S4
  7. Affected versionversion=24.2 <24.2R1-S2, 24.2R2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Juniper Networks · Junos OSversion=0 <21.2R3-S9; version=21.4 <21.4R3-S10; version=22.2 <22.2R3-S6; version=22.4 <22.4R3-S6; version=23.2 <23.2R2-S3; version=23.4 <23.4R2-S4; version=24.2 <24.2R1-S2, 24.2R2

Published CVSS scores

6.7Juniper NetworksCVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
4.4Juniper NetworksCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-653Improper Isolation or Compartmentalization
T1055Process Injection

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Reported exploitation

Technologies

Your stack

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Your stack

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