The Speedup Optimization plugin for WordPress is vulnerable to Missing Authorization in all versions up to and including 1.5.9. The `speedup01_ajax_enabled()` function, which handles the `wp_ajax_speedup01_enabled` AJAX action, does not perform any capability check via `current_user_can()` and also lacks nonce verification. This is in contrast to other AJAX handlers in the same plugin (e.g., `speedup01_ajax_install_iox` and `speedup01_ajax_delete_cache_file`) which properly check for `install_plugins` and `manage_options` capabilities respectively. This makes it possible for authenticated attackers, with Subscriber-level access and above, to enable or disable the site's optimization module by sending a POST request to admin-ajax.
Conclusion & alert: CVE-2026-4127 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 | 0.03% | 0.21% | +0.18% |
| 2 | 2026-03-21 | — | 0.03% | — |
Full EPSS history (2 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 |
|---|---|---|---|
| No affected products in dataset. | |||