CVE-2021-28667: Stackstorm

High severity, CVSS 7.5. EPSS: 2.5% chance of exploitation in the next 30 days.

StackStorm before 3.4.1, in some situations, has an infinite loop that consumes all available memory and disk space. This can occur if Python 3.x is used, the locale is not utf-8, and there is an attempt to log Unicode data (from an action or rule name).

Affected products

• Stackstorm Stackstorm: before 3.4.1 (fixed in 3.4.1)

Published 2021-03-18. Last modified 2026-06-17.