Administrator-level stored XSS via XML-RPC custom fields
Published Jun 9, 2026 · Updated Jun 9, 2026
Stored XSS in Lazy Blocks before 4.3.0 allows remote authenticated users to execute JavaScript in visitors' browsers. The XML-RPC custom_fields path writes lazyblocks_code_frontend_html post metadata with add_post_meta() without enforcing the plugin's editor-side unfiltered_html check. Exploitation requires an Administrator account that lacks unfiltered_html, XML-RPC access, and a visitor to load a page embedding the malicious block.
Summary
What happened
Stored XSS in Lazy Blocks before 4.3.0 allows remote authenticated users to execute JavaScript in visitors' browsers. The XML-RPC custom_fields path writes lazyblocks_code_frontend_html post metadata with add_post_meta() without enforcing the plugin's editor-side unfiltered_html check. Exploitation requires an Administrator account that lacks unfiltered_html, XML-RPC access, and a visitor to load a page embedding the malicious block.
The record
- CVE
- CVE-2026-8981
- Published
- Jun 9, 2026
- Updated
- Jun 9, 2026
- Vendor
- Devoice LLC
- Product
- Lazy Blocks
- Classifications
- CWE-79, T1203
- Attack vector
- network
- Privileges
- admin
Timeline
How it unfolded
- Jun 9, 2026CVE publishedPublication date reported by the CVE source.
- Jun 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <4.3.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- WPScan XML-RPC custom_fields proof of conceptfunctional · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo