# CVE-2026-19224: Hummingbird Performance privilege escalation in network settings

Source: https://junglewise.ai/threats/cve-2026-19224-hummingbird-performance-privilege-escalation-in-network-settings  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-04. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-19224 · Severity: high · CVSS 7.2 · Published 2026-09-04

Hummingbird Performance is a popular WordPress plugin that optimizes website speed and performance. A vulnerability in versions before 3.21.2 allows an administrator of any single website on a multisite network to modify network-wide settings and execute arbitrary code across the entire network. This could result in complete compromise of all websites hosted on the affected multisite installation.

Vendors: [WPMU DEV](https://junglewise.ai/threats/vendors/wpmu-dev).

## Quick answers

**Is CVE-2026-19224 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-19224 being exploited in the wild.

**How severe is CVE-2026-19224?** High severity, with a CVSS score of 7.2, published 4 September 2026.

**Which products and versions are affected?** WPMU DEV Hummingbird Performance before 3.21.2.

**Is there a fix for CVE-2026-19224?** A patch was published on 2026-09-04: Fixed in version 3.21.2 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-19224 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-19224?** Check whether you run WPMU DEV Hummingbird Performance at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The plugin fails to properly restrict access to network-wide settings to network administrators only, allowing a regular site administrator to modify these settings. The vulnerability is rooted in inadequate authorization checks on the Hub Connector functionality. An authenticated site administrator on a multisite WordPress network can leverage this to inject and execute arbitrary code across all sites on the network. This is a privilege escalation attack that requires administrative access to at least one site in the multisite network. The fix is available in version 3.21.2 and later.

## Affected products

- WPMU DEV Hummingbird Performance before 3.21.2

## Timeline

- 2026-09-02: disclosed
- 2026-09-04: patched: Fixed in version 3.21.2

## References

- [https://wpscan.com/vulnerability/443461c5-93c4-49b4-a5c2-057b7afa4ce6/](https://wpscan.com/vulnerability/443461c5-93c4-49b4-a5c2-057b7afa4ce6/)