Vulnerability in Juniper Junos

CVE-2025-52949

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.

EPSS: 0.003 (17.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-52949?
CVE-2025-52949 is a medium-severity vulnerability in Juniper Junos, classified under Improper Handling of Length Parameter Inconsistency. CVSS score: 6.5/10. Published 2025-07-11.
How severe is CVE-2025-52949?
Medium severity. CVSS v3 base score is 6.5 out of 10.
Is CVE-2025-52949 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.