CVE-2026-101986: Junos OS and Junos OS Evolved: J-Web permits pre-authentication CGI execution

Published Oct 14, 2026

Updated

An Improper Authentication vulnerability in J-Web of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated network attacker to bypass J-Web authentication and execute CGI content with elevated privileges via a crafted HTTP request.

Affected Software

2 affected components

Juniper Networks Junos OS

Juniper Networks Junos OS Evolved

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade Juniper Junos OS Evolved to a version that resolves this vulnerability.
Fixed in 23.2R2-S7.7-EVO
Upgrade
Upgrade Juniper Junos OS Evolved to a version that resolves this vulnerability.
Fixed in 23.4R2-S8.11-EVO
Upgrade
Upgrade Juniper Junos OS Evolved to a version that resolves this vulnerability.
Fixed in 24.2R2-S5.6-EVO
Upgrade
Upgrade Juniper Junos OS Evolved to a version that resolves this vulnerability.
Fixed in 24.4R2-S5-EVO
Upgrade
Upgrade Juniper Junos OS Evolved to a version that resolves this vulnerability.
Fixed in 25.2R2-S2-EVO
Upgrade
Upgrade Juniper Junos OS Evolved to a version that resolves this vulnerability.
Fixed in 25.2X100-D35-EVO
Upgrade
Upgrade Juniper Junos OS Evolved to a version that resolves this vulnerability.
Fixed in 25.4R1-S3-EVO
Upgrade
Upgrade Juniper Junos OS Evolved to a version that resolves this vulnerability.
Fixed in 25.4R2-EVO
Upgrade
Upgrade Juniper Junos OS Evolved to a version that resolves this vulnerability.
Fixed in 25.4X300-D40-EVO
Upgrade
Upgrade Juniper Junos OS Evolved to a version that resolves this vulnerability.
Fixed in 26.2R1-S2-EVO
Upgrade
Upgrade Juniper Junos OS Evolved to a version that resolves this vulnerability.
Fixed in 26.2R2-EVO
Upgrade
Upgrade Juniper Junos OS Evolved to a version that resolves this vulnerability.
Fixed in 26.4R1-EVO
Upgrade
Upgrade Juniper Junos OS to a version that resolves this vulnerability.
Fixed in 23.2R2-S7.7
Upgrade
Upgrade Juniper Junos OS to a version that resolves this vulnerability.
Fixed in 23.4R2-S8.13
Upgrade
Upgrade Juniper Junos OS to a version that resolves this vulnerability.
Fixed in 24.2R2-S5.5
Upgrade
Upgrade Juniper Junos OS to a version that resolves this vulnerability.
Fixed in 24.4R2-S5
Upgrade
Upgrade Juniper Junos OS to a version that resolves this vulnerability.
Fixed in 25.2R2-S2
Upgrade
Upgrade Juniper Junos OS to a version that resolves this vulnerability.
Fixed in 25.4R1-S3
Upgrade
Upgrade Juniper Junos OS to a version that resolves this vulnerability.
Fixed in 25.4R2
Upgrade
Upgrade Juniper Junos OS to a version that resolves this vulnerability.
Fixed in 26.2R1-S2
Upgrade
Upgrade Juniper Junos OS to a version that resolves this vulnerability.
Fixed in 26.2R2
Upgrade
Upgrade Juniper Junos OS to a version that resolves this vulnerability.
Fixed in 26.4R1

Event History

Oct 14, 2026

CVE Published

via MITRE·04:20 PM

Data Sourced

via MITRE·04:20 PM

RemedyDescriptionSeverityWeakness

Frequently Asked Questions

Who can exploit this issue?

An unauthenticated attacker who can reach the J-Web HTTP service over the network can exploit it. No credentials or user interaction are required.

What level of access can successful exploitation provide?

The attacker can bypass J-Web authentication and execute CGI content with elevated privileges. The reported impact includes high confidentiality, integrity, and availability impact.

Which products are affected?

The affected products listed are Juniper Networks Junos OS and Juniper Networks Junos OS Evolved. The provided information does not identify specific affected or fixed release versions.