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

published 2021-09-23 5y ago modified 2026-06-17 4mo ago also EUVD-2021-23448

cvss: 5.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.6%; EPSS 0.6% chance of exploitation in 30 days, percentile 48%
public exploits: 0; none known

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

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CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: last yr. (2025-03-28)

Exploit prediction

0.59% chance of exploitation in the next 30 days, higher than 48% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by	version	score	vector
CNA	3.1	5.5	CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N
NVD	3.1	5.4	CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
NVD	2.0	3.5	AV:N/AC:M/Au:S/C:N/I:P/A:N

Affected products

Hector Cabrera WordPress Popular Posts

Classification

Weakness

CWE-79 Improper Neutralization of Input During Web Page Generation

Technology feeds

WordPress rss critical rss

References

github.com /cabrerahector/wordpress-popular-posts/blob/master/changelog.md
release-notes, third-party-advisory
patchstack.com /database/vulnerability/wordpress-popular-posts/wordpress-popular-posts-plugin-5-3-3-authenticated-persistent-
third-party-advisory

Sources

CVE List CVE-2021-36872
NVD CVE-2021-36872

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