Security Flaw in All in One SEO WordPress Plugin Allows Unauthorized Shortcode Execution
CVE-2026-19856

6.5MEDIUM

Key Information:

Vendor

WordPress
Status
All In One Seo
Vendor
CVE Published:
2 October 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-19856?

The All in One SEO plugin for WordPress versions prior to 5.0.2.1 contains a significant security flaw that fails to properly identify shortcodes in user-generated content. This oversight permits unauthenticated users to execute arbitrary shortcodes that are registered on any affected site. Additionally, for sites that have been upgraded from earlier plugin versions, necessary protections may be completely disabled, further increasing the exposure to potential exploitation without the need for crafted input.

Affected Version(s)

All in One SEO 0 < 5.0.2.1

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-19856 - Proof of Concept

References

https://wpscan.com/vulnerability/e35365d3-65de-45a7-9629-...
exploitvdb-entrytechnical-description

CVSS V3.1

Score:
6.5
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

Jakub Herman
WPScan
.