CVE-2021-3835

Buffer overflow in usb device class

8.2 High

Buffer overflow in usb device class. Zephyr versions >= v2.6.0 contain Heap-based Buffer Overflow (CWE-122). For more information, see https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-fm6v-8625-99jf

Attack profile

How easy it is to exploit

Attack vector: Adjacent network
Complexity: High
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: Low
Integrity: High
Availability: High

Exploit likelihood

0.74%Down 0.1 points since Feb 8, 2022

What each source reports

CVE List Score used 8.2

Buffer overflow in usb device class

Record: CVE-2021-3835
CVSS 3.1: 8.2 HighCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:H
Weakness: CWE-122
Updated: 2026-11-02

EUVDEUVD-2021-27082 8.2

Record: EUVD-2021-27082
CVSS 3.1: 8.2 HighCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:H
Updated: 2026-11-03

NVD 8.2

Record: CVE-2021-3835
CVSS 3.1: 8.2 HighCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:H
CVSS 3.1: 8.8 HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 2.0: 5.8 MediumAV:A/AC:L/Au:N/C:P/I:P/A:P
Weakness: CWE-122, CWE-787
Updated: 2026-11-02

OSVUBUNTU-CVE-2021-3835 8.2

Record: UBUNTU-CVE-2021-3835
CVSS 3.1: 8.2 HighCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:H
CVSS 3.1: 8.8 HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`zephyr` Ubuntu:16.04:LTS	All versions, plus listed versions 3.1.2-13.1.2-1build1	None known
`zephyr` Ubuntu:18.04:LTS	All versions, plus listed versions 3.1.2-1build13.1.2-1build2	None known
`zephyr` Ubuntu:20.04:LTS	All versions, plus listed versions 3.1.2-1build3	None known
`zephyr` Ubuntu:22.04:LTS	All versions, plus listed versions 3.1.2-1build3	None known
`zephyr` Ubuntu:24.04:LTS	All versions, plus listed versions 3.1.2-1.13.1.2-1.1build1	None known
`zephyr` Ubuntu:25.10	All versions, plus listed versions 3.1.2-1.1build1	None known
`zephyr` Ubuntu:26.10	All versions, plus listed versions 3.1.2-4	None known
`zephyr` Ubuntu:26.04:LTS	All versions, plus listed versions 3.1.2-1.1build13.1.2-4	None known

History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases, published	EUVD
Nov 2, 2026	first indexed	CVE List, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-3835 is a high vulnerability (CVSS 8.2) in Zephyrproject Zephyr, published February 7, 2022. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.74%, the 54th percentile. No source names a fixed version.