Vulnerability in Juniper Junos

CVE-2025-52955

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.

EPSS: 0.003 (18.8th 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-2025-52955?
CVE-2025-52955 is a medium-severity vulnerability in Juniper Junos, classified under Incorrect Calculation of Buffer Size. CVSS score: 6.5/10. Published 2025-07-11.
How severe is CVE-2025-52955?
Medium severity. CVSS v3 base score is 6.5 out of 10.
Is CVE-2025-52955 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.