Shield Security <= 21.0.8 - Unauthenticated Reflected Cross-Site Scripting via 'message' Parameter
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-79.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| paultgoodchild | Shield: Blocks Bots, Protects Users, and Prevents Security Breaches | up to 21.0.8 | — | No fix listed | CNA |
- Shield: Blocks Bots, Protects Users, and Prevents Security Breaches Vendorpaultgoodchild Affected up to 21.0.8 Fixed in — No fix listed CNA
CPE names Threatist (inferred) · 1
Inferred from how NVD named this product before; not given by a source.
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:getshieldsecurity:shield_security:*:*:*:*:*:*:*:* | — | — | Getshieldsecurity |
- cpe:2.3:a:getshieldsecurity:shield_security:*:*:*:*:*:*:*:* Versions — — ·Getshieldsecurity
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-0561
- 2026-10-03 Alias added: GHSA-wpqj-w3wq-pqjv
- 2026-10-18 EPSS moved to the 50th–90th percentile
References
Other 3
- https://www.wordfence.com/threat-intel/vulnerabilities/id/cb49eb5f-c1ff-4440-8b53-c2515e65da27?source=cve
- https://research.cleantalk.org/cve-2026-0561
- 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=
More paultgoodchild vulnerabilities
- TI-2026-83515 Stored cross-site scripting in Shield Security via request path CVSS 3.1HIGH 7.2
- TI-2026-00509 Shield Security <= 21.0.8 - Cross-Site Request Forgery to SQL Injection CVSS 3.1MEDIUM 6.5
- TI-2025-14019 Shield Security <= 21.0.9 - Authenticated (Subscriber+) Insecure Direct Object Reference to Disable Google Authenticator CVSS 3.1MEDIUM 4.3
- TI-2025-13178 Missing authorization in paultgoodchild Shield: Blocks Bots, Protects Users, and Prevents… CVSS 3.1MEDIUM 4.3
- TI-2024-04046 Shield Security – Smart Bot Blocking & Intrusion Prevention Security <= 19.1.13 - Cross-Site Request Forgery CVSS 3.1MEDIUM 4.3
Sources
- CVE-2026-0561 · CVE Program
- CVE-2026-0561 · NVD
- FIRST EPSS
- GHSA-wpqj-w3wq-pqjv · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences