CVE-2021-33176

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-06-08 · updated 2026-06-17
Weakness: CWE-502

Description

VerneMQ MQTT Broker versions prior to 1.12.0 are vulnerable to a denial of service attack as a result of excessive memory consumption due to the handling of untrusted inputs. These inputs cause the message broker to consume large amounts of memory, resulting in the application being terminated by the operating system.

Affected products

vernemq: before 1.12.0 — fixed in 1.12.0

How to fix

Upgrade to a fixed version: vernemq 1.12.0. Check the vendor advisory for mitigations.

References

https://www.synopsys.com/blogs/software-security/cyrc-advisory-rabbitmq-emqx-vernemq
https://www.synopsys.com/blogs/software-security/cyrc-advisory-rabbitmq-emqx-vernemq

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