CVE-2025-52955: Juniper Junos

Medium severity, CVSS 6.5. EPSS: 0.3% chance of exploitation in the next 30 days.

An Incorrect Calculation of Buffer Size vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent unauthenticated attacker to cause a memory corruption that leads to a rpd crash.  When the logical interface using a routing instance flaps continuously, specific updates are sent to the jflow/sflow modules. This results in memory corruption, leading to an rpd crash and restart.  Continued receipt of these specific updates will cause a sustained Denial of Service condition. This issue affects Junos OS: * All versions before 21.2R3-S9, * All versions of 21.4, * All versions of 22.2, * from 22.4 before 22.4R3-S7, * 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 of 21.2-EVO,  * All versions of 21.4-EVO,  * All versions of 22.2-EVO,  * from 22.4 before 22.4R3-S7-EVO,  * from 23.2 before 23.2R2-S3-EVO,  * from 23.4 before 23.4R2-S4-EVO,  * from 24.2 before 24.2R2-EVO.

Affected products

• Juniper Junos: before 21.2 (fixed in 21.2); version 21.2 only; version 21.4 only; version 22.2 only; version 22.4 only; version 23.2 only; …
• Juniper Junos OS Evolved: version 21.2 only; version 21.4 only; version 22.2 only; version 22.4 only; version 23.2 only; version 23.4 only; …

Published 2025-07-11. Last modified 2026-06-17.