CVE-2021-41036

Name: CVE-2021-41036
Creator: NVD / NIST
Published: 2021-11-03T00:15:08.023+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 1.17%

Last modified Jun 17, 2026

CVE-2021-41036 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. In versions prior to 1.1 of the Eclipse Paho MQTT C Client, the client does not check rem_len size in readpacket.. EPSS estimates a 1.17% chance of exploitation in the next 30 days.

Description

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

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

1.17%

63.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Eclipse	Paho Mqtt C\/C\+\+ Client	< 1.1.0

References

https://github.com/eclipse/paho.mqtt.embedded-c/issues/96Issue Tracking, Patch, Third Party Advisory
https://github.com/eclipse/paho.mqtt.embedded-c/issues/96Issue Tracking, Patch, Third Party Advisory

Timeline

Published: Nov 3, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-41036?

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

How severe is CVE-2021-41036?

CVE-2021-41036 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 1.17% probability of exploitation in the next 30 days.

How do I fix CVE-2021-41036?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-41036?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST