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.
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.003 (19.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 20th percentile — 19.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000
Affected products
- Juniper Junos — versions 21.2, 21.4, 22.2
- Juniper Junos OS Evolved — versions 21.2, 21.4, 22.2
- Juniper Networks Junos OS — versions 0, 21.4, 22.2
- Juniper Networks Junos OS Evolved — versions 0, 21.4, 22.2
Weakness classification (CWE)
Public proof-of-concept exploits
References
- supportportal.juniper.net/JSA100062 (vendor-advisory, Vendor Advisory)
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.