CVE-2021-36226

Name: CVE-2021-36226
Creator: NVD / NIST
Published: 2023-02-06T14:15:08.97+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 0.81%

Last modified Jun 17, 2026

CVE-2021-36226 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. Western Digital My Cloud devices before OS5 do not use cryptographically signed Firmware upgrade files.. EPSS estimates a 0.81% chance of exploitation in the next 30 days.

Description

Western Digital My Cloud devices before OS5 do not use cryptographically signed Firmware upgrade files.

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

0.81%

52.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Westerndigital	My Cloud Os	< 5.02.104

References

https://github.com/pedrib/PoC/blob/master/advisories/Pwn2Own/Tokyo_2020/weekend_destroyer/weekend_destroyer.mdExploit, Patch, Third Party Advisory
https://krebsonsecurity.com/2021/07/another-0-day-looms-for-many-western-digital-users/Exploit, Patch, Third Party Advisory
https://www.youtube.com/watch?v=vsg9YgvGBecExploit, Patch, Third Party Advisory
https://github.com/pedrib/PoC/blob/master/advisories/Pwn2Own/Tokyo_2020/weekend_destroyer/weekend_destroyer.mdExploit, Patch, Third Party Advisory
https://krebsonsecurity.com/2021/07/another-0-day-looms-for-many-western-digital-users/Exploit, Patch, Third Party Advisory
https://www.youtube.com/watch?v=vsg9YgvGBecExploit, Patch, Third Party Advisory

Timeline

Published: Feb 6, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-36226?

Western Digital My Cloud devices before OS5 do not use cryptographically signed Firmware upgrade files.

How severe is CVE-2021-36226?

CVE-2021-36226 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.81% probability of exploitation in the next 30 days.

How do I fix CVE-2021-36226?

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-2021-36226?

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

Scan your code now

Source: NVD / NIST