What’s Vulnerable › Vulnerabilities

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

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-07-11 · updated 2026-06-17
• Weakness: CWE-130

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.

Affected products

• Juniper Junos OS: before 21.4; 21.4, 21.4-r1, 21.4-r1-s1, 21.4-r1-s2, 21.4-r2, 21.4-r2-s1 (+66) — fixed in 21.4
• Juniper Networks Junos OS Evolved: before 22.2; 22.2, 22.2-r1, 22.2-r1-s1, 22.2-r1-s2, 22.2-r2, 22.2-r2-s1 (+47) — fixed in 22.2

How to fix

Upgrade to a fixed version: Juniper Junos OS 21.4; Juniper Networks Junos OS Evolved 22.2. Check the vendor advisory for mitigations.

References

• https://supportportal.juniper.net/JSA100053

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