Custom Block Builder – Lazy Blocks <= 4.2.0 — Authenticated (Contributor+) Remote Code Execution
CVE-2026-1560Published · Updated Action summary
Affected: ≤4.2.0Update to 4.2.1 or newer
All remediation steps- Severity
- High8.8
- CVSS
- 8.8CVSS 3.1 · CNA (Wordfence)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HWhat does this vector mean?
AV:NAttack vector- Network
AC:LAttack complexity- Low
PR:LPrivileges required- Low
UI:NUser interaction- None
S:UScope- Unchanged
C:HConfidentiality- High
I:HIntegrity- High
A:HAvailability- High
- Required access
- Unknown
- Exploit prediction (EPSS)
- No score
- CISA KEV
- Not listed
On this page8
Am I affected?
Custom Block Builder – Lazy Blocks lazy-blocks
- Affected≤ 4.2.0
- Patched in4.2.1
Update to 4.2.1 or newer.
You are affected if you run ≤ 4.2.0. Version 4.2.1 and later are not affected by this issue.
- Check your version: in wp-admin go to Plugins → Installed Plugins and read the version under Custom Block Builder – Lazy Blocks.
- No admin access? Run a passive check of your site. It reads public files only.
What to do
- Update to version 4.2.1, or a newer patched version
- Rotate administrator passwords and application secrets if the site ran a vulnerable version while publicly reachable.
- Watch Custom Block Builder – Lazy Blocks to get an email when the next vulnerability is published.
Advisory
Source description from Wordfence Intelligence, credited to Youssef Elouaer.
The Custom Block Builder – Lazy Blocks plugin for WordPress is vulnerable to Remote Code Execution in all versions up to, and including, 4.2.0 via multiple functions in the 'LazyBlocks_Blocks' class. This makes it possible for authenticated attackers, with Contributor-level access and above, to execute code on the server.
Exploits & references
Proof-of-concept & detection
No public proof-of-concept or detection template is known for this vulnerability.
Advisories & patches
- Advisorywordfence.com
Related CVEs
More in Custom Block Builder – Lazy Blocks
All 4| Severity | Vulnerability | CVE | Published |
|---|---|---|---|
| Medium4.4 | Authenticated (Administrator+) Stored Cross-Site Scripting <4.3.0Update to 4.3.0 | CVE-2026-8981 | |
| Medium4.3 | Missing Authorization ≤4.1.0Update to 4.1.1 | CVE-2025-58258 | |
| Medium6.1 | Reflected Cross-Site Scripting ≤3.8.2Update to 3.8.3 | CVE-2024-12878 |
- Medium4.4Authenticated (Administrator+) Stored Cross-Site Scripting
<4.3.0Update to 4.3.0
- Medium4.3Missing Authorization
≤4.1.0Update to 4.1.1
- Medium6.1Reflected Cross-Site Scripting
≤3.8.2Update to 3.8.3
Timeline
CVE published
Severity high, CVSS 8.8
Record last updated
Sources & licenses
Wordfence record- Vulnerability data
- Wordfence Intelligence. Copyright 2012-2026 Defiant Inc. Licensed under the CC BY-SA 4.0.
- CVE® identifiers
- Copyright 1999-2026 The MITRE Corporation. Used under the CVE Program. CVE® is a registered trademark of The MITRE Corporation.
- CVSS / CWE
- National Vulnerability Database (NVD), shown unmodified. This product uses the NVD API but is not endorsed or certified by the NVD.
- VulnCrest content
- Summary, remediation guidance and page layout © VulnCrest. Not sourced from NVD.