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CVE-2025-21590

4.4, medium Known exploited

Juniper Junos OS Improper Isolation or Compartmentalization Vulnerability

NVD (opens in a new tab) CVE.org (opens in a new tab) CISA KEV catalogue (opens in a new tab)
CVSS
4.4, medium medium CVSS v3.1
EPSS, next 30 days
2% higher than 77.2% of scored CVEs
Exploitation
Confirmed in the wild
Published
12 Mar 2025a year ago

Known exploited

CISA added this to the Known Exploited Vulnerabilities Catalog on 13 Mar 2025. US federal agencies had to remediate by 3 Apr 2025, a deadline that has passed.

Required action. Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Description

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.

Details

Vendor
Juniper
Product
Junos OS
Weakness
CWE-653 (opens in a new tab)
Status
Analyzed
Updated
1 Oct 2026
Assigner
sirt@juniper.net

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N

References 3

Advisories 2

Other references 1

The kind is read from NVD's tags where present and from the shape of the URL otherwise, so treat it as a hint.

Other Juniper CVEs

Every Juniper CVE we hold

Same vendor in what we hold, not a known link between the flaws.

  • CVE-2023-36851 Juniper Junos OS SRX Series Missing Authentication for Critical Function Vulnerability KEV EPSS 1% 5.3, medium
  • CVE-2023-36844 Juniper Junos OS EX Series PHP External Variable Modification Vulnerability KEV EPSS 90% 5.3, medium
  • CVE-2023-36845 Juniper Junos OS EX Series and SRX Series PHP External Variable Modification Vulnerability KEV EPSS 95% 9.8, critical
  • CVE-2023-36846 Juniper Junos OS SRX Series Missing Authentication for Critical Function Vulnerability KEV EPSS 93% 5.3, medium
  • CVE-2023-36847 Juniper Junos OS EX Series Missing Authentication for Critical Function Vulnerability KEV EPSS 83% 5.3, medium
  • CVE-2020-1631 Juniper Junos OS Path Traversal Vulnerability KEV EPSS 5% 9.8, critical
  • CVE-2015-7755 Juniper ScreenOS Improper Authentication Vulnerability KEV EPSS 61% 9.8, critical

Beyond this page

Is CVE-2025-21590 in your network?

This page tells you how dangerous CVE-2025-21590 is out there. Whether it sits on one of your devices, only a scan of your own network can tell. That is what our systems do, every day, for the companies we protect.

CVE-2025-21590 is in the CISA catalogue of exploited vulnerabilities: attackers are already exploiting it.

  • EXYS7600 OCELOT

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  • EXYS7950 KONDRA

    Detect it if it's exploited

    Until the patch is applied, Kondra monitors your network, events and endpoints in real time. It keeps an inventory of the software installed on every endpoint, and its anomaly detection rules flag what an attacker does once inside.

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Check your exposure

Assembled from the NVD 2.0 API, the CISA Known Exploited Vulnerabilities Catalog and FIRST EPSS. Scores are as of our last collection on 17 Oct 2026, not the live upstream state.