Critical severity · published Nov 25, 2021
CVE-2021-44223
WordPress before 5.8 lacks support for the Update URI plugin header
9.8
CVSS
29%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)29.0% · higher than 98% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
WO
WordPress · WordPress
before 5.8 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-44223
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-44223
Release Notes
https://make.wordpress.org/core/2021/06/29/introducing-update-uri-plugin-header-in-wordpress-5-8/
Exploit
https://vavkamil.cz/2021/11/25/wordpress-plugin-confusion-update-can-get-you-pwned/
More from WordPress
9.8
CVE-2026-63030
WordPress < 7.0.2 - REST API batch-route confusion and SQL injection issue leading to Remote Code Execution
9.8
CVE-2020-25213
WordPress File Manager Plugin Remote Code Execution Vulnerability
9.8
CVE-2016-10033
The mailSend function in the isMail transport in PHPMailer before 5.2.18 might allow remote attackers to pass extra parameters to the mail command and consequently execute…
8.1
CVE-2026-87902
WordPress Core Remote File Inclusion Vulnerability
7.5
CVE-2020-11738
WordPress Snap Creek Duplicator Plugin File Download Vulnerability