Back

HIGH

Junos OS and Junos OS Evolved: BGP update with a set of specific attributes causes rpd crash

Published Jan 15, 2026

Description

A Buffer Over-read vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS).

When an affected device receives a BGP update with a set of specific optional transitive attributes over an established peering session, rpd will crash and restart when attempting to advertise the received information to another peer. This issue can only happen if one or both of the BGP peers of the receiving session are non-4-byte-AS capable as determined from the advertised capabilities during BGP session establishment. Junos OS and Junos OS Evolved default behavior is 4-byte-AS capable unless this has been specifically disabled by configuring:

[ protocols bgp ... disable-4byte-as ]

Established BGP sessions can be checked by executing:

show bgp neighbor <IP address> | match "4 byte AS"

This issue affects:

Junos OS: 

* all versions before 22.4R3-S8, * 23.2 versions before 23.2R2-S5, * 23.4 versions before 23.4R2-S6, * 24.2 versions before 24.2R2-S2, * 24.4 versions before 24.4R2;

Junos OS Evolved: 

* all versions before 22.4R3-S8-EVO, * 23.2 versions before 23.2R2-S5-EVO, * 23.4 versions before 23.4R2-S6-EVO, * 24.2 versions before 24.2R2-S2-EVO, * 24.4 versions before 24.4R2-EVO.

Affected products

Remediation

Vendor solution

The following software releases have been updated to resolve this specific issue: Junos OS Evolved: 22.4R3-S8-EVO, 23.2R2-S5-EVO, 23.4R2-S6-EVO, 24.2R2-S2-EVO, 24.4R2-EVO, 25.2R1-EVO, and all subsequent releases; Junos OS: 22.4R3-S8, 23.2R2-S5, 23.4R2-S6, 24.2R2-S2, 24.4R2, 25.2R1, and all subsequent releases.

Weaknesses (1)

References (2)

Change history (0)

No recorded changes yet.

Sources
CVE.org / MITRE
Status PUBLISHED
Assigner juniper
Published Jan 15, 2026
Updated Jan 15, 2026
Reserved Sep 23, 2025
CISA Vulnrichment
Updated Jan 15, 2026
NVD
Status Analyzed
Modified Jun 17, 2026
Red Hat
Severity n/a
Public date n/a