Is CVE-2021-41036 actively exploited?

No active exploitation of CVE-2021-41036 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-41036 be exploited remotely?

Yes. CVE-2021-41036 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-41036?

CVE-2021-41036 has a CVSS score of 9.8 (CRITICAL).

HOME VULNERABILITIESCVE-2021-41036

CRITICAL

CVE-2021-41036

CWE-787Published: November 3, 2021· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official Description

In versions prior to 1.1 of the Eclipse Paho MQTT C Client, the client does not check rem_len size in readpacket.

NVD Source

Technical Analysis

CVE-2021-41036 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

From a weakness classification perspective (CWE-787): Out-of-bounds write vulnerabilities can lead to data corruption, crashes, or arbitrary code execution.