Incorrect Synchronization Vulnerability in Juniper Networks Junos OS and Junos OS Evolved
CVE-2026-21919

7.1HIGH

Key Information:

Vendor

Juniper Networks
Status
Junos Os
Junos Os Evolved
Vendor
CVE Published:
9 April 2026

Badges

👾 Exploit Exists

What is CVE-2026-21919?

An Incorrect Synchronization vulnerability in the management daemon of Juniper Networks' Junos OS and Junos OS Evolved enables low privilege attackers to trigger a complete Denial-of-Service (DoS) condition in the management plane. Specifically, when NETCONF sessions are rapidly initiated and terminated, a locking issue arises, causing mgd processes to hang, preventing further logins and device management. Recovery requires a power-cycle, highlighting the critical need for users to monitor mgd process states and implement timely updates to mitigate the risks associated with this vulnerability.

Affected Version(s)

Junos OS 23.4 < 23.4R2-S4

Junos OS 24.2 < 24.2R2-S1

Junos OS 24.4 < 24.4R1-S3, 24.4R2

References

https://kb.juniper.net/JSA106019
vendor-advisory

CVSS V4

Score:
7.1
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

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