Juniper Junos OS Evolved prior 25.4R1-EVO/25.4R1-S1-EVO/25.4R2-EVO permission assignment

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
9.6	$5k-$25k	0.00

Summaryinfo

A vulnerability labeled as very critical has been found in Juniper Junos OS Evolved. The affected element is an unknown function. The manipulation results in permission assignment. This vulnerability is identified as CVE-2026-21902. The attack can be executed remotely. There is not any exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability, which was classified as very critical, was found in Juniper Junos OS Evolved. Affected is an unknown part. The manipulation with an unknown input leads to a permission assignment vulnerability. CWE is classifying the issue as CWE-732. The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

An Incorrect Permission Assignment for Critical Resource vulnerability in the On-Box Anomaly detection framework of Juniper Networks Junos OS Evolved on PTX Series allows an unauthenticated, network-based attacker to execute code as root. The On-Box Anomaly detection framework should only be reachable by other internal processes over the internal routing instance, but not over an externally exposed port. With the ability to access and manipulate the service to execute code as root a remote attacker can take complete control of the device. Please note that this service is enabled by default as no specific configuration is required. This issue affects Junos OS Evolved on PTX Series: * 25.4 versions before 25.4R1-S1-EVO, 25.4R2-EVO. This issue does not affect Junos OS Evolved versions before 25.4R1-EVO. This issue does not affect Junos OS.

The advisory is available at supportportal.juniper.net. This vulnerability is traded as CVE-2026-21902 since 01/05/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 03/30/2026).

Upgrading to version 25.4R1-EVO, 25.4R1-S1-EVO or 25.4R2-EVO eliminates this vulnerability.

The vulnerability is also documented in the databases at EUVD (EUVD-2026-8693) and CERT Bund (WID-SEC-2026-0535). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

Juniper JUNOS

Productinfo

Type

Router Operating System

Vendor

Juniper

Name

Junos OS Evolved

License

commercial

Website

Vendor: https://www.juniper.net/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 9.8
VulDB Meta Temp Score: 9.6

VulDB Base Score: 9.8
VulDB Temp Score: 9.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 9.8
CNA Vector (juniper): 🔒

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Permission assignment
CWE: CWE-732 / CWE-275 / CWE-266
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Junos OS Evolved 25.4R1-EVO/25.4R1-S1-EVO/25.4R2-EVO

Timelineinfo

01/05/2026 CVE reserved
02/25/2026 +51 days Advisory disclosed
02/25/2026 +0 days VulDB entry created
03/30/2026 +33 days VulDB entry last update

Sourcesinfo

Vendor: juniper.net

Advisory: JSA107128
Status: Confirmed

CVE: CVE-2026-21902 (🔒)
GCVE (CVE): GCVE-0-2026-21902
GCVE (VulDB): GCVE-100-347826
EUVD: 🔒
CERT Bund: WID-SEC-2026-0535 - Juniper JUNOS Evolved: Schwachstelle ermöglicht Ausführen von beliebigem Programmcode mit Administratorrechten

Entryinfo

Created: 02/25/2026 18:36
Updated: 03/30/2026 21:36
Changes: 02/25/2026 18:36 (79), 02/25/2026 20:38 (1), 02/27/2026 03:34 (7), 03/04/2026 10:13 (1), 03/30/2026 21:36 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.