What is CVE-2026-121636?

CVE-2026-121636 is a medium-severity vulnerability in Quick Event Manager, classified under Insufficient Verification of Data Authenticity. CVSS score: 5.3/10. Published 2026-11-06.

How severe is CVE-2026-121636?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Vulnerability in Quick Event Manager

CVE-2026-121636

The Quick Event Manager WordPress plugin before 9.19 does not verify the authenticity of PayPal payment notifications before marking event registrations as paid, which could allow unauthenticated attackers to mark registrations as paid without making a payment.

Published 2026-11-06 · last modified 2026-11-06.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

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

Quick Event Manager

Weakness classification (CWE)

CWE-345 — Insufficient Verification of Data Authenticity

References

wpscan.com/vulnerability/04b181e1-639c-476f-b66b-2a073bf36829/ (technical-description, exploit, vdb-entry)

Frequently asked questions

What is CVE-2026-121636?: CVE-2026-121636 is a medium-severity vulnerability in Quick Event Manager, classified under Insufficient Verification of Data Authenticity. CVSS score: 5.3/10. Published 2026-11-06.
How severe is CVE-2026-121636?: Medium severity. CVSS v3 base score is 5.3 out of 10.