Buffer overflow in Juniper Junos OS Evolved
CVE-2025-59969
A Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') vulnerability in the advanced forwarding toolkit (evo-aftmand/evo-pfemand) of Juniper Networks Junos OS Evolved on PTX Series or QFX5000 Series allows an unauthenticated, adjacent attacker to cause a Denial of Service (DoS).An attacker sending crafted multicast packets will cause line cards running evo-aftmand/evo-pfemand to crash and restart or non-line card devices to crash and restart. Continued receipt and processing of these packets will sustain the Denial of Service (DoS) condition. This issue affects Junos OS Evolved PTX Series: * All versions before 22.4R3-S8-EVO, * from 23.2 before 23.2R2-S5-EVO, * from 23.4 before 23.4R2-EVO, * from 24.2 before 24.2R2-EVO, * from 24.4 before 24.4R2-EVO. This issue affects Junos OS Evolved on QFX5000 Series: * 22.2-EVO version before 22.2R3-S7-EVO, * 22.4-EVO version before 22.4R3-S7-EVO, * 23.2-EVO versions before 23.2R2-S4-EVO, * 23.4-EVO versions before 23.4R2-S5-EVO, * 24.2-EVO versions before 24.2R2-S1-EVO, * 24.4-EVO versions before 24.4R1-S3-EVO, 24.4R2-EVO. This issue does not affect Junos OS Evolved on QFX5000 Series versions before: 21.2R2-S1-EVO, 21.2R3-EVO, 21.3R2-EVO, 21.4R1-EVO, and 22.1R1-EVO.
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: 0.002 (7.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 7th percentile — 7.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000
Affected products
Weakness classification (CWE)
References
- kb.juniper.net/JSA103159 (vendor-advisory, Vendor Advisory)
Frequently asked questions
- What is CVE-2025-59969?
- CVE-2025-59969 is a medium-severity vulnerability in Juniper Junos OS Evolved, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 6.5/10. Published 2026-04-09.
- How severe is CVE-2025-59969?
- Medium severity. CVSS v3 base score is 6.5 out of 10.