What is CVE-2026-11855?

CVE-2026-11855 is a high-severity vulnerability in Simple Membership, classified under CWE-79 CROSS-SITE SCRIPTING (XSS). CVSS score: 8.8/10. Published 2026-07-06.

How severe is CVE-2026-11855?

High severity. CVSS v3 base score is 8.8 out of 10.

Vulnerability in Simple Membership

CVE-2026-11855

The Simple Membership WordPress plugin before 4.7.5 does not verify the authenticity of Stripe webhook requests when no signing secret is configured, nor escape a value taken from them before outputting it in an administrator notice, allow…

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

Affected products

Unknown Simple Membership — versions 0

References

contact@wpscan.com (technical-description, exploit, vdb-entry)

Frequently asked questions

What is CVE-2026-11855?: CVE-2026-11855 is a high-severity vulnerability in Simple Membership, classified under CWE-79 CROSS-SITE SCRIPTING (XSS). CVSS score: 8.8/10. Published 2026-07-06.
How severe is CVE-2026-11855?: High severity. CVSS v3 base score is 8.8 out of 10.