CVE-2024-12878
Custom Block Builder – Lazy Blocks < 3.8.3 - Reflected XSS
The Custom Block Builder WordPress plugin before 3.8.3 does not sanitise and escape a parameter before outputting it back in the page, leading to a Reflected Cross-Site Scripting which could be used against high privilege users such as admin.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
Custom Block Builder – Lazy Blocks < 3.8.3 - Reflected XSS
The Custom Block Builder WordPress plugin before 3.8.3 does not sanitise and escape a parameter before outputting it back in the page, leading to a Reflected Cross-Site Scripting which could be used against high privilege users such as admin.
- Record
CVE-2024-12878- CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L - Updated
- 2026-11-02
EUVDEUVD-2025-5312
The Custom Block Builder WordPress plugin before 3.8.3 does not sanitise and escape a parameter before outputting it back in the page, leading to a Reflected Cross-Site Scripting which could be used against high privilege users such as admin.
- Record
EUVD-2025-5312- CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-7c47-rxv3-c2fv
The Custom Block Builder WordPress plugin before 3.8.3 does not sanitise and escape a parameter...
The Custom Block Builder WordPress plugin before 3.8.3 does not sanitise and escape a parameter before outputting it back in the page, leading to a Reflected Cross-Site Scripting which could be used against high privilege users such as admin.
- Record
GHSA-7c47-rxv3-c2fv- CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L - Weakness
- CWE-79
- Updated
- 2026-11-02
NVD
The Custom Block Builder WordPress plugin before 3.8.3 does not sanitise and escape a parameter before outputting it back in the page, leading to a Reflected Cross-Site Scripting which could be used against high privilege users such as admin.
- Record
CVE-2024-12878- CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L - Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| Nuclei | Lazy Blocks <= 3.8.2 - Cross-Site Scripting |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, Nuclei, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2024-12878 is a high vulnerability (CVSS 7.1) in Thedevoice Lazy Blocks, published February 26, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.62%, the 49th percentile. No source names a fixed version.