CVE-2026-11366 — MonsterInsights < 11.1.0 - Unauthenticated Measurement Protocol Secret Update via Empty-Key HMAC Bypass
The MonsterInsights WordPress plugin before 11.1.0 does not correctly validate the signature on one of its unauthenticated AJAX actions: when the MonsterInsights WordPress plu…
Published: 2026-08-04 · CVSS: 3.7 · CVSS 3.1
The MonsterInsights WordPress plugin before 11.1.0 does not correctly validate the signature on one of its unauthenticated AJAX actions: when the MonsterInsights WordPress plugin before 11.1.0 is not connected to Google Analytics the HMAC signing key is empty, which lets unauthenticated attackers forge a valid signature and overwrite a MonsterInsights WordPress plugin before 11.1.0 configuration value, disrupting the MonsterInsights WordPress plugin before 11.1.0's server-side analytics in Manual GA4 mode.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7