CVE-2025-52946: Junos OS and Junos OS Evolved: With traceoptions enabled, receipt of malformed AS PATH causes RPD crash

A Use After Free vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Juniper Networks Junos OS Evolved allows an attacker sending a BGP update with a specifically malformed AS PATH to cause rpd to crash, resulting in a Denial of Service (DoS). Continuous receipt of the malformed AS PATH attribute will cause a sustained DoS condition.

On all Junos OS and Junos OS Evolved platforms, the rpd process will crash and restart when a specifically malformed AS PATH is received within a BGP update and traceoptions are enabled.

This issue only affects systems with BGP traceoptions enabled and requires a BGP session to be already established. Systems without BGP traceoptions enabled are not impacted by this issue.

This issue affects:

Junos OS:

All versions before 21.2R3-S9,  all versions of 21.4, from 22.2 before 22.2R3-S6,  from 22.4 before 22.4R3-S5,  from 23.2 before 23.2R2-S3,  from 23.4 before 23.4R2-S4,  from 24.2 before 24.2R2;

Junos OS Evolved:

All versions before 22.4R3-S5-EVO,  from 23.2-EVO before 23.2R2-S3-EVO,  from 23.4-EVO before 23.4R2-S4-EVO,  from 24.2-EVO before 24.2R2-EVO.

This is a more complete fix for previously published CVE-2024-39549 (JSA83011).