CVE-2025-52949 Junos OS and Junos OS Evolved: In an EVPN environment, receipt of specifically malformed BGP update causes RPD crash

High 7.1 Published Updated

A malformed BGP packet can crash the routing daemon in EVPN-enabled Junos OS devices, causing a denial of service.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Local or same network only
Victim action needed
Not needed
Fix
None listed

What is CVE-2025-52949?

CVE-2025-52949 is a high-severity denial of service vulnerability in Juniper Junos, published on 11 Jul 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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.

Weakness: CWE-130

Which versions are affected by CVE-2025-52949?

It affects 2 products.

Products include Juniper Junos, Juniper Junos Os Evolved.

How do I fix CVE-2025-52949?

No fix has been published for CVE-2025-52949 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2025-52949 being exploited?

There is no known exploitation of CVE-2025-52949 in the wild and no public exploit code.

All Juniper Junos vulnerabilities

Sources

Also known as GHSA-fx8c-8vrh-7hg5.

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