CVE-2026-11366 — MonsterInsights < 11.1.0 - Unauthenticated Measurement Protocol Secret Update via Empty-Key HMAC Bypass

Description (CNA)

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.

Affected (CNA)

Vendor / product	Versions
Unknown / MonsterInsights	affected 0 before 11.1.0

CWE

No CWE identifiers supplied.

References

https://wpscan.com/vulnerability/283331ca-cc2e-4c2c-9e3b-2e8c6f0c84d2/

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.