Your MCU Likely Escaped the eMudhra Intermediate CA Compromise
Following the disclosure of the eMudhra Intermediate CA Compromise, software engineers and security experts have debated the impact on IoT and microcontroller-class devices. While Linux-based single board computers face risks if unpatched, microcontroller fleets are generally unaffected.
Why it matters
Certificate authority compromises pose severe Man-in-the-Middle security risks for connected hardware, making software supply chain visibility critical.
If you are a software engineer, or generally work in the tech industry, there is a good chance that you heard about the eMudhra Intermediate CA Compromise that was disclosed yesterday (October 20, 2026). If you don't, you may have noticed an uptick in software updates for various products that you use.
I won't go through the entire background of the situation as there are plenty of other posts, including the now public bug report from Mozilla, that describe the details of the compromise. However, I have had a number of folks reach out regarding the impact on IoT devices, specifically microcontroller (MCU) class devices. Some of them may have been motivated by the discourse around the compromise, such as Russ Cox's Bluesky post , which included the following sentence.
IOT boxes that can't or don't update are now trivially MITM'able forever.
Get smarter about the news
Sign up free for a feed built around what you actually care about, Dive Deeper research on any story, and the full text of every article.
Create free accountAlready have an account? Sign in