The Event Monster – Event Management, Events Calendar, Tickets plugin for WordPress is vulnerable...

Description

The Event Monster – Event Management, Events Calendar, Tickets plugin for WordPress is vulnerable to Insufficient Verification of Data Authenticity in versions up to, and including, 2.1.0. This is due to the capture_payment() AJAX handler (registered via wp_ajax_nopriv_em_capture_payment) trusting client-supplied payment data — including transaction ID, amount, and payment status — without performing any server-side verification against the PayPal API or any other payment gateway, and without nonce or capability checks. This makes it possible for unauthenticated attackers to forge payment records, mark bookings as Completed, and obtain confirmation emails containing valid QR code tickets without making any actual payment.

Basic information

Type
unreviewed
Severity
medium
Advisory on GitHub
Open advisory ↗
Repository advisory
Source code
Not specified
Published (advisory)
2026-06-06 00:31:39 UTC
Updated
2026-06-06 00:33:35 UTC
NVD published
2026-06-05

EPSS Score

Score Percentile
0.02% 4.78%

CVSS Scores

Base score Version Severity Vector
5.3 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.

Identifiers

CWEs

CWE id Name
CWE-345 Insufficient Verification of Data Authenticity

References

cvelogic Threat Intelligence