SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-3966

usb device bluetooth class includes a buffer overflow related to implementation of net_buf_add_mem.

HIGH 8.8EPSS 0.50%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.50%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

usb device bluetooth class includes a buffer overflow related to implementation of net_buf_add_mem.

CVSS 3.1
8.8 HIGHCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
0.50% probability · 43th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-122, CWE-120
Affected
zephyrproject/zephyr
Source
vulnerabilities@zephyrproject.org
EPSS trend
0%3%5%26 October 2026: 0.50%26 October 202626 October 2026

EPSS 0.5% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.