CVE-2024-39551: Juniper Junos

High severity, CVSS 7.5. EPSS: 0.5% chance of exploitation in the next 30 days.

An Uncontrolled Resource Consumption vulnerability in the H.323 ALG (Application Layer Gateway) of  Juniper Networks Junos OS on SRX Series and MX Series with SPC3 and MS-MPC/MIC, allows an unauthenticated network-based attacker to send specific packets causing traffic loss leading to Denial of Service (DoS).  Continued receipt and processing of these specific packets will sustain the Denial of Service condition. The memory usage can be monitored using the below command.   user@host> show usp memory segment sha data objcache jsf  This issue affects SRX Series and MX Series with SPC3 and MS-MPC/MIC:  *  20.4 before 20.4R3-S10,  *  21.2 before 21.2R3-S6,  *  21.3 before 21.3R3-S5,  *  21.4 before 21.4R3-S6,  *  22.1 before 22.1R3-S4,  *  22.2 before 22.2R3-S2,  *  22.3 before 22.3R3-S1,  *  22.4 before 22.4R3,  *  23.2 before 23.2R2.

Affected products

• Juniper Junos: version 20.4 only; version 21.2 only; version 21.3 only; version 21.4 only; version 22.1 only; version 22.2 only; …

Published 2024-07-11. Last modified 2026-06-17.