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Servers and applications · WordPress plugins

CVE-2021-24153

Yoast SEO – Advanced SEO with real-time guidance and built-in AI: Cross-site Scripting

Severity
Medium 5.4
Published
2 Aug 2016
Last changed
17 Jun 2026
Added to UpHeron
21 Oct 2026
Fixed in
3.4.1
Also known as
WPV-e79c4c8ed273
Sources
NVD, WPVulnerability

Description

A Stored Cross-Site Scripting vulnerability was discovered in the Yoast SEO WordPress plugin before 3.4.1, which had built-in blacklist filters which were blacklisting Parenthesis as well as several functions such as alert but bypasses were found.

Affected software

SoftwareAffected versions
Yoast SEOServers and applications · cpe:a:yoast:yoast_seo
  • Every version before 3.4.1
Yoast SEOWordPress plugins · wp-plugin:wordpress-seo
  • Every version before 3.4.1

References

  • NVD https://nvd.nist.gov/vuln/detail/CVE-2021-24153
  • CVE.org https://www.cve.org/CVERecord?id=CVE-2021-24153
  • Wordfence https://www.wordfence.com/threat-intel/vulnerabilities/wordpress-plugins/wordpress-seo/yoast-seo-340-authenticated-stored-cross-site-scripting