Buffer overflow in Zephyrproject-Rtos Zephyr

CVE-2025-9557

‭An out-of-bound write can lead to an arbitrary code execution. Even on devices with some form of memory protection, this can still lead to‬ ‭a crash and a resultant denial of service.‬

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.6 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H.

EPSS exploit prediction

EPSS: 0.002 (9.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 10th percentile — 9.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-9557: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-9557?
CVE-2025-9557 is a high-severity vulnerability in Zephyrproject-Rtos Zephyr, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 7.6/10. Published 2025-11-26.
How severe is CVE-2025-9557?
High severity. CVSS v3 base score is 7.6 out of 10.