CVE-2026-0561
Shield Security <= 21.0.8 - Unauthenticated Reflected Cross-Site Scripting via 'message' Parameter
CVSS Score
6.1
EPSS Score
0.0%
EPSS Percentile
0th
The Shield Security plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the 'message' parameter in all versions up to, and including, 21.0.8 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.
| CWE | CWE-79 |
| Vendor | paultgoodchild |
| Product | shield: blocks bots, protects users, and prevents security breaches |
| Published | Feb 19, 2026 |
| Last Updated | Apr 8, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
Affected Versions
paultgoodchild / Shield: Blocks Bots, Protects Users, and Prevents Security Breaches
0 ≤ 21.0.8
References
wordfence.com: https://www.wordfence.com/threat-intel/vulnerabilities/id/cb49eb5f-c1ff-4440-8b53-c2515e65da27?source=cve research.cleantalk.org: https://research.cleantalk.org/cve-2026-0561 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3439494%40wp-simple-firewall&new=3439494%40wp-simple-firewall&sfp_email=&sfph_mail=
Credits
Dmitrii Ignatyev