The WPUpper Share Buttons plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 3.51. This is due to missing or incorrect nonce validation on the 'save_custom_css_request' function. This makes it possible for unauthenticated attackers to inject custom CSS to modify a site via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.
Conclusion & alert: CVE-2024-13883 is rated Low Risk (21.1/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.21%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.07% | 0.21% | +0.14% |
| 2 | 2026-04-01 | 0.01% | 0.07% | +0.06% |
| 3 | 2025-11-21 | — | 0.01% | — |
Full EPSS history (5 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 4.3 | 3.1 | MEDIUM |
|
2.8 | 1.4 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| victorfreitas | wpupper_share_buttons | <= 3.51 | cpe:2.3:a:victorfreitas:wpupper_share_buttons:*:*:*:*:*:wordpress:*:* |