cvedb.io
CVE-2025-21594
HIGH · CVSS 7.5
EPSS exploitation probability: 0%
Published 2025-04-09T20:15:25.620 · Last modified 2026-06-17T08:43:48.513

Summary

An Improper Check for Unusual or Exceptional Conditions vulnerability in the pfe (packet forwarding engine) of Juniper Networks Junos OS on MX Series causes a port within a pool to be blocked leading to Denial of Service (DoS). In a DS-Lite (Dual-Stack Lite) and NAT (Network Address Translation) scenario, when crafted IPv6 traffic is received and prefix-length is set to 56, the ports assigned to the user will not be freed.  Eventually, users cannot establish new connections. Affected FPC/PIC need to be manually restarted to recover. Following is the command to identify the issue:      user@host> show services nat source port-block      Host_IP                     External_IP                   Port_Block      Ports_Used/       Block_State/                                            

Affected products

juniper — junos

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.