CVE-2025-52946

HIGH

Juniper Junos OS and Junos OS Evolved - Denial of Service via Malformed BGP AS PATH Attribute

Title source: llm
STIX 2.1

Description

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).

References (1)

Core 1
Core References
Vendor Advisory vendor-advisory
https://supportportal.juniper.net/JSA100050

Scores

CVSS v3 7.5
EPSS 0.0040
EPSS Percentile 61.0%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-416
Status published
Products (6)
juniper/junos 21.2 (16 CPE variants)
juniper/junos 21.4
juniper/junos 22.2 (13 CPE variants)
juniper/junos 22.4 (12 CPE variants)
juniper/junos 23.2 (7 CPE variants)
juniper/junos 23.4
Published Jul 11, 2025
Tracked Since Feb 18, 2026