CVE-2026-57026 Juniper Networks CVE debrief

Who should care

Security teams and administrators responsible for Juniper Networks Junos OS on MX Series with SPC3 and SRX Series should prioritize patching, as this vulnerability allows for a Denial-of-Service (DoS) attack.

Technical summary

The vulnerability exists in the SIP plugin of Juniper Networks Junos OS on MX Series with SPC3 and SRX Series. An unauthenticated, network-based attacker can exploit this by sending a malformed SIP invite packet, which causes the flow processing daemon (flowd) to crash and restart. This results in a complete service outage until the system automatically recovers. Affected versions include all versions before 23.2R2-S7, 23.4 versions before 23.4R2-S8, 24.2 versions before 24.2R2-S5, 24.4 versions before 24.4R2-S4, 25.2 versions before 25.2R2, and 25.4 versions before 25.4R1-S2.

Defensive priority

High priority should be given to patching Juniper Networks Junos OS on MX Series with SPC3 and SRX Series due to the high CVSS score of 8.7 and the potential for Denial-of-Service (DoS) attacks.

Recommended defensive actions

• Apply patches for affected Juniper Networks Junos OS versions on MX Series with SPC3 and SRX Series.
• Disable SIP ALG if not required.
• Monitor for suspicious SIP traffic.
• Implement compensating controls such as rate limiting for SIP traffic.
• Verify system configurations and inventory for affected systems.

Evidence notes

The CVE record was published on 2026-07-09T22:17:07.923Z and was last modified on 2026-07-10T15:16:45.013Z. The NVD entry is currently Received. Limited details are available about the specific conditions and vectors of the vulnerability, emphasizing the need for patching and monitoring.

Official resources