CVE-2021-36872 MEDIUM

CVE-2021-36872: WordPress Popular Posts plugin <= 5.3.3 - Authenticated Persistent Cross-Site Scripting (XSS) vulnerability

Vendor Hector Cabrera

Product WordPress Popular Posts

Weakness CWE-79 · XSS

Published September 23, 2021

Last update April 28, 2026

View on NVD All CVEs

CVSS base score

5.5/10

Attack vector Network

Attack complexity Low

Privileges required High

User interaction None

Confidentiality Low

Integrity Low

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N

What the vulnerability does

01Description

Authenticated Persistent Cross-Site Scripting (XSS) vulnerability in WordPress Popular Posts plugin (versions <= 5.3.3). Vulnerable at &widget-wpp[2][post_type].

Explanation of Vulnerability in Simple Terms

02Summary

WordPress Popular Posts versions 5.3.3 contain a stored cross-site scripting (XSS) vulnerability. An authenticated administrator can inject malicious JavaScript that executes in the browsers of other site users. The vulnerability affects the plugin's scope across the site, potentially compromising user sessions and data. Update to a version newer than 5.3.3.

What an attacker can do

03Attacker Capabilities

Inject JavaScript that runs in other users' browsers when they view affected pages.

Potential impact on your site

04Site Impact

A compromised admin account can inject malicious scripts affecting all site visitors and other administrators.

Conditions required to exploit

05Prerequisites

Attacker must have administrator privileges on the WordPress site.

Key dates

06Disclosure timeline

September 23, 2021 CVE published

April 28, 2026 Record updated

External resources

07References

NVD — National Vulnerability Database https://nvd.nist.gov/vuln/detail/CVE-2021-36872 CWE — Common Weakness Enumeration https://cwe.mitre.org/data/definitions/79.html AskarLabs — CWE-79 write-up Cross-Site Scripting

Related vulnerabilities

Identifiers

CVE CVE-2021-36872

CWE CWE-79

CVSS 5.5 / MEDIUM

Affected versions