CVE-2021-44223

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 29.0% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2021-11-25 · updated 2026-06-17

Description

WordPress before 5.8 lacks support for the Update URI plugin header. This makes it easier for remote attackers to execute arbitrary code via a supply-chain attack against WordPress installations that use any plugin for which the slug satisfies the naming constraints of the WordPress.org Plugin Directory but is not yet present in that directory.

Affected products

WordPress: before 5.8 — fixed in 5.8

How to fix

Upgrade to a fixed version: WordPress 5.8. Check the vendor advisory for mitigations.

References

https://make.wordpress.org/core/2021/06/29/introducing-update-uri-plugin-header-in-wordpress-5-8/
https://vavkamil.cz/2021/11/25/wordpress-plugin-confusion-update-can-get-you-pwned/
https://make.wordpress.org/core/2021/06/29/introducing-update-uri-plugin-header-in-wordpress-5-8/
https://vavkamil.cz/2021/11/25/wordpress-plugin-confusion-update-can-get-you-pwned/

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