An Access of Uninitialized Pointer vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved with BGP sharding configured allows an attacker triggering indirect next-hop updates, along with timing outside the attacker's control, to cause rpd to crash and restart, leading to a Denial of Service (DoS).

With BGP sharding enabled, triggering route resolution of an indirect next-hop (e.g., an IGP route change over which a BGP route gets resolved), may cause rpd to crash and restart. An attacker causing continuous IGP route churn, resulting in repeated route re-resolution, will increase the likelihood of triggering this issue, leading to a potentially extended DoS condition.

This issue affects:

Junos OS:

• all versions before 21.4R3-S6, 
• from 22.1 before 22.1R3-S6, 
• from 22.2 before 22.2R3-S3, 
• from 22.3 before 22.3R3-S3, 
• from 22.4 before 22.4R3, 
• from 23.2 before 23.2R2; 

Junos OS Evolved: 

• all versions before 22.3R3-S3-EVO, 
• from 22.4 before 22.4R3-EVO, 
• from 23.2 before 23.2R2-EVO.

Versions before Junos OS 21.3R1 and Junos OS Evolved 21.3R1-EVO are unaffected by this issue.

Systems are only vulnerable to this issue if BGP sharding is enabled. For example:

[ system processes routing bgp rib-sharding ]

Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

This issue was seen during production usage.

The following software releases have been updated to resolve this specific issue:
Junos OS 21.4R3-S6, 22.1R3-S6, 22.2R3-S3, 22.3R3-S3, 22.4R3, 23.2R2, 23.4R1, and all subsequent releases.
Junos OS Evolved 22.3R3-S3-EVO, 22.4R3-EVO, 23.2R2-EVO, 23.4R1-EVO, and all subsequent releases.

This issue is being tracked as 1756068 which is visible on the Customer Support website.

Note: Juniper SIRT's policy is not to evaluate releases which are beyond End of Engineering (EOE) or End of Life (EOL).

Temporarily disabling BGP sharding will mitigate this issue.

2025-10-08: Initial Publication

• KB16613: Overview of the Juniper Networks SIRT Quarterly Security Bulletin Publication Process [juniper.net]
• KB16765: In which releases are vulnerabilities fixed? [juniper.net]
• KB16446: Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories [juniper.net]
• Report a Security Vulnerability - How to Contact the Juniper Networks Security Incident Response Team