An Improper Handling of Length Parameter Inconsistency vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows a logically adjacent BGP peer sending a specifically malformed BGP packet to cause rpd to crash and restart, resulting in a Denial of Service (DoS). Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition.

Only systems configured for Ethernet Virtual Private Networking (EVPN) signaling are vulnerable to this issue. 

This issue affects iBGP and eBGP, and both IPv4 and IPv6 are affected by this vulnerability.

This issue affects:

Junos OS: 

• all versions before 21.4R3-S11, 
• from 22.2 before 22.2R3-S7, 
• from 22.4 before 22.4R3-S7, 
• from 23.2 before 23.2R2-S4, 
• from 23.4 before 23.4R2-S5, 
• from 24.2 before 24.2R2-S1, 
• from 24.4 before 24.4R1-S3, 24.4R2; 

Junos OS Evolved: 

• all versions before 22.2R3-S7-EVO, 
• from 22.4-EVO before 22.4R3-S7-EVO, 
• from 23.2-EVO before 23.2R2-S4-EVO, 
• from 23.4-EVO before 23.4R2-S5-EVO, 
• from 24.2-EVO before 24.2R2-S1-EVO, 
• from 24.4-EVO before 24.4R1-S3-EVO, 24.4R2-EVO.

This issue only affects systems configured for EVPN signaling.  For example:

[protocols bgp family evpn signaling]

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

This issue was discovered during external security research.

The following software releases have been updated to resolve this specific issue:

Junos OS: 21.4R3-S11, 22.2R3-S7, 22.4R3-S7, 23.2R2-S4, 23.4R2-S5, 24.2R2-S1, 24.4R1-S3, 24.4R2, 25.2R1, and all subsequent releases.
Junos OS Evolved: 22.2R3-S7-EVO, 22.4R3-S7-EVO, 23.2R2-S4-EVO, 23.4R2-S5-EVO, 24.2R2-S1-EVO, 24.4R1-S3-EVO, 24.4R2-EVO, 25.2R1-EVO, and all subsequent releases.

This issue is being tracked as 1863170 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).

There are no known workarounds for this issue.

2025-07-09: 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
• https://www.cve.org/CVERecord?id=CVE-2025-52949

Juniper SIRT would like to acknowledge and thank Craig Dods from Meta’s Infrastructure Security Engineering team for responsibly reporting this vulnerability.