Buffer overflow in Juniper 2x100ge \+ 4x10ge Mpc5e
CVE-2025-52952
An Out-of-bounds Write vulnerability in the connectivity fault management (CFM) daemon of Juniper Networks Junos OS on MX Series with MPC-BUILTIN, MPC1 through MPC9 line cards allows an unauthenticated adjacent attacker to send a malformed packet to the device, leading to an FPC 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. This issue affects Juniper Networks: Junos OS: * All versions before 22.2R3-S1, * from 22.4 before 22.4R2. This feature is not enabled by default.
Vulnerability class: Buffer Overflow
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 (17.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 18th percentile — 17.6% 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
Weakness classification (CWE)
References
- supportportal.juniper.net/JSA100058 (vendor-advisory, Vendor Advisory)
- www.juniper.net/documentation/us/en/software/junos/network-mgmt/topics/topic-ma… (Product, technical-description)
Frequently asked questions
- What is CVE-2025-52952?
- CVE-2025-52952 is a medium-severity vulnerability in Juniper 2x100ge \+ 4x10ge Mpc5e, classified under Out-of-bounds Write. CVSS score: 6.5/10. Published 2025-07-11.
- How severe is CVE-2025-52952?
- Medium severity. CVSS v3 base score is 6.5 out of 10.