SB2026050828 - Local denial of service in Junos OS and Junos OS Evolved

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Main Vulnerability Database SB2026050828

SB2026050828 - Local denial of service in Junos OS and Junos OS Evolved

Published: May 8, 2026

Security Bulletin ID SB2026050828
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Race condition (CVE-ID: CVE-2026-21919)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a remote user to cause a denial of service.

The vulnerability exists due to incorrect synchronization in the management daemon (mgd) when handling rapid NETCONF session establishment and disconnection. A remote user can repeatedly connect and disconnect NETCONF sessions to cause a denial of service.

Only devices with NETCONF enabled are exposed. When the maximum number of mgd processes is reached, no new logins are possible, and recovery requires a power-cycle.


Remediation

Install update from vendor's website.

References