What’s Vulnerable › Vulnerabilities

CVE-2026-8900: Simple SEO Slideshow <= 1.2.8 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode Attributes

• Severity: medium (CVSS 6.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-06 · updated 2026-07-23
• Weakness: CWE-79

Description

The Simple SEO Slideshow plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Shortcode Attributes in all versions up to, and including, 1.2.8 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. WordPress KSES does not strip malicious shortcode attribute values on post save, allowing contributor-level users to persist payloads that execute for any visitor, including administrators reviewing the post.

Affected products

• spyrosvl Simple SEO Slideshow: through 1.2.8

References

• https://plugins.trac.wordpress.org/browser/simple-seo-slideshow/trunk/simpleslideshow.php#L235
• https://plugins.trac.wordpress.org/browser/simple-seo-slideshow/trunk/simpleslideshow.php#L334
• https://plugins.trac.wordpress.org/browser/simple-seo-slideshow/trunk/simpleslideshow.php#L356
• https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3551425%40simple-seo-slideshow&new=3551425%40simple-seo-slideshow&sfp_email=&sfph_mail=
• https://www.wordfence.com/threat-intel/vulnerabilities/id/3b3bb703-fdff-4525-9272-7a3db58b81a0?source=cve

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