CVE-2026-121763

MEDIUM 6.5

WordPress Hummingbird plugin <= 3.21.2 - Cross Site Scripting (XSS) vulnerability

CVSS Score

6.5

EPSS Score

0.0%

EPSS Percentile

0th

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in WPMU DEV Hummingbird hummingbird-performance allows Stored XSS.This issue affects Hummingbird: from n/a through 3.21.2.

CWE	CWE-79
Vendor	wpmu dev
Product	hummingbird
Published	Nov 9, 2026
Last Updated	Nov 9, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

Low

Affected Versions

WPMU DEV / Hummingbird

0 ≤ 3.21.2

References

NVD ↗ CVE.org ↗ EPSS Data ↗

patchstack.com: https://patchstack.com/database/wordpress/plugin/hummingbird-performance/vulnerability/wordpress-hummingbird-plugin-3-21-2-cross-site-scripting-xss-vulnerability?_s_id=cve

Credits

mroccon | Patchstack Bug Bounty Program