PatchTheCVECVE-2026-21919: An Incorrect Synchronization vulnerability in the management daemon (mgd) of Juniper Networks Junos OS and Jun
CVE-2026-21919 is a medium-severity flaw (CVSS 6.5) affecting junos, junos os evolved. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
An Incorrect Synchronization vulnerability in the management daemon (mgd) of Juniper Networks Junos OS and Junos OS Evolved allows a network-based attacker with low privileges to cause a complete Denial-of-Service (DoS) of the management plane. When NETCONF sessions are quickly established and disconnected, a locking issue causes mgd processes to hang in an unusable state. When the maximum number of mgd processes has been reached, no new logins
Why this priority
- No elevated risk signals yet
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 6.5 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | Low |
| User interaction | None |
| EPSS exploit chance | 0.2% (top 86%) |
| CISA exploited list | No |
| Weakness | CWE-821 |
| Published | 2026-04-09 |
| Last modified | 2026-10-26 |
Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-21919?
junos: mitigate or apply the listed mitigation; junos os evolved: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.
Is CVE-2026-21919 being exploited?
CVE-2026-21919 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-21919 affect?
CVE-2026-21919 affects junos, junos os evolved. Severity is medium (CVSS 6.5). An Incorrect Synchronization vulnerability in the management daemon (mgd) of Juniper Networks Junos OS and Junos OS Evolved allows a network-based attacker with low privileges to cause a complete Denial-of-Service (DoS) of the management pl
How urgent is CVE-2026-21919?
Priority 26/100. No elevated risk signals yet.
Software pages
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