What is CVE-2026-121763?

CVE-2026-121763 is a medium-severity vulnerability in Wpmu Dev Hummingbird, classified under Cross-site Scripting. CVSS score: 6.5/10. Published 2026-11-09.

How severe is CVE-2026-121763?

Medium severity. CVSS v3 base score is 6.5 out of 10.

XSS in Wpmu Dev Hummingbird

CVE-2026-121763

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.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2026-11-09 · last modified 2026-11-09.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Wpmu Dev Hummingbird

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

patchstack.com/database/wordpress/plugin/hummingbird-performance/vulnerability/… (vdb-entry)

Frequently asked questions

What is CVE-2026-121763?: CVE-2026-121763 is a medium-severity vulnerability in Wpmu Dev Hummingbird, classified under Cross-site Scripting. CVSS score: 6.5/10. Published 2026-11-09.
How severe is CVE-2026-121763?: Medium severity. CVSS v3 base score is 6.5 out of 10.