CVE-2020-10062

Packet length decoding error in MQTT

9.0 Critical

An off-by-one error in the Zephyr project MQTT packet length decoder can result in memory corruption and possible remote code execution. NCC-ZEP-031 This issue affects: zephyrproject-rtos zephyr version 2.2.0 and later versions.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: High
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

2.88%Up 1.0 points since Apr 14, 2021

What each source reports

CVE List Score used 9.0

Packet length decoding error in MQTT

Record: CVE-2020-10062
CVSS 3.1: 9.0 CriticalCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Weakness: CWE-193
Updated: 2026-11-02

EUVDEUVD-2020-2527 9.0

Record: EUVD-2020-2527
CVSS 3.1: 9.0 CriticalCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Updated: 2026-11-03

GitHub AdvisoriesGHSA-5rf5-gcg9-hrpr No score

An off-by-one error in the Zephyr project MQTT packet length decoder can result in memory...

Record: GHSA-5rf5-gcg9-hrpr
Updated: 2026-11-02

NVD 9.0

Record: CVE-2020-10062
CVSS 3.1: 9.0 CriticalCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 2.0: 7.5 HighAV:N/AC:L/Au:N/C:P/I:P/A:P
Weakness: CWE-193
Updated: 2026-11-02

Affected products

History

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

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

In short

CVE-2020-10062 is a critical vulnerability (CVSS 9.0) in Zephyrproject Zephyr, published June 5, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.88%, the 86th percentile. No source names a fixed version.