CVE-2026-121636— Quick Event Manager 9.9.5 - 9.18 - Unauthenticated PayPal IPN Verification Bypass via the 'debug' Parameter
Quick assessment
Affected
Unknown Quick Event Manager
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.
Quick Event Manager WordPress 插件在 9.19 版本之前，未验证 PayPal 支付通知的真实性，即在将活动报名标记为“已支付”前未进行校验。这可能导致未经身份验证的攻击者在未实际付款的情况下，将报名状态标记为已支付。
Possible ATT&CK Techniques 1 AI
T1190 · Exploit Public-Facing Application
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I. Basic Information for CVE-2026-121636
Vulnerability Information
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Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.
Vulnerability Title
Quick Event Manager 9.9.5 - 9.18 - Unauthenticated PayPal IPN Verification Bypass via the 'debug' Parameter
Source: CVE Program / CVE List V5
Vulnerability Description
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.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Affected Products
| Vendor | Product | Affected Versions | CPE | Subscribe |
|---|---|---|---|---|
| Unknown | Quick Event Manager | 9.9.5 ~ 9.19 | - |
|
II. Public POCs for CVE-2026-121636
| # | POC Description | Source Link | Shenlong Link |
|---|
AI-Generated POC
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No public POC found.
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Other References for CVE-2026-121636 (1)
-
https://wpscan.com/vulnerability/04b181e1-639c-476f-b66b-2a073bf36829/ exploit vdb-entry technical-description
Same Patch Batch · Unknown · 2026-11-06 · 30 CVEs total
| CVE-2026-118423 | 10.0 CRITICAL | WP Libre Form 1.5.0.1 - Unauthenticated RCE via Arbitrary File Upload |
| CVE-2026-88800 | 9.1 CRITICAL | MDJM Event Management and Mobile Events Manager <= 1.7.8.7 - Unauthenticated Arbitrary Rol |
| CVE-2026-88799 | 8.8 HIGH | MDJM Event Management and Mobile Events Manager <= 1.7.8.7 - Subscriber+ Account Takeover |
| CVE-2026-88801 | 8.0 HIGH | MDJM Event Management and Mobile Events Manager <= 1.7.8.7 - Subscriber+ Stored XSS via Ro |
| CVE-2026-121633 | 5.3 MEDIUM | Order Tracking < 3.6.0 - Unauthenticated Payment Confirmation Forgery via PayPal IPN Liste |
| CVE-2026-118166 | 4.8 MEDIUM | MC4WP: Mailchimp for WordPress < 4.15.0 - Unauthenticated Arbitrary Shortcode Execution vi |
| CVE-2026-113615 | GS JWT Authentication <= 1.0.0 - Unauthenticated Privilege Escalation via SQLi | |
| CVE-2026-118239 | AutomatorWP < 6.0.7 - Unauthenticated Zoom/AWeber Integration Connection Hijack via OAuth | |
| CVE-2026-118188 | PublishPress Revisions 3.9.0 - 4.2.0 - Subscriber+ Unpublished Content Disclosure | |
| CVE-2026-115673 | Anti-Spam by CleanTalk < 6.91 - Unauthenticated Stored XSS via Comment Author Email | |
| CVE-2026-118167 | MC4WP: Mailchimp for WordPress < 4.15.0 - Unauthenticated Subscription Audience Override | |
| CVE-2026-118187 | PublishPress Revisions < 4.3.1 - Contributor+ Unpublished Content Disclosure via IDOR | |
| CVE-2026-118186 | PublishPress Revisions 3.6.0 - 4.2.0 - Contributor+ Unapproved Content Publishing via Revi | |
| CVE-2026-86606 | iubenda < 3.13.7 - Unauthenticated Stored XSS via Cookie Block HTML Parser | |
| CVE-2026-110813 | Advanced Custom Fields (ACF®) < 6.8.11 - Unauthenticated Stored XSS via HTML Attribute Nam | |
| CVE-2026-110525 | MCB Stats <= 1.0.0 - Unauthenticated Stored XSS via User-Agent | |
| CVE-2026-92396 | Blocks for ShopEngine < 2.4.4 - Contributor+ Stored XSS via gutenova_store_css | |
| CVE-2026-12967 | WCFM Membership < 2.12.1 - Subscriber+ Payment Verification Bypass | |
| CVE-2026-87784 | Cool Media Filter <= 1.0.1 - Subscriber+ Privilege Escalation via role_permission | |
| CVE-2026-119259 | All-in-One Video Gallery < 5.1.0 - Unauthenticated Views and Duration Post Meta Write |
Showing top 20 of 30 CVEs. View all on vendor page → →
IV. Related Vulnerabilities
Same product: Quick Event Manager
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CVE-2026-82214
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CVE-2026-84847
WordPress Quick Event Manager plugin <= 9.17 - Broken Access -
CVE-2026-84848
WordPress Quick Event Manager plugin <= 9.17 - Cross Site Sc -
CVE-2023-23975
WordPress Quick Event Manager plugin <= 9.7.4 - Broken Acces -
CVE-2023-23979
WordPress Quick Event Manager Plugin <= 9.7.4 is vulnerable
Same vendor: Unknown
-
CVE-2026-121633
Order Tracking < 3.6.0 - Unauthenticated Payment Confirmatio -
CVE-2026-118166
MC4WP: Mailchimp for WordPress < 4.15.0 - Unauthenticated Ar -
CVE-2026-118423
WP Libre Form 1.5.0.1 - Unauthenticated RCE via Arbitrary Fi -
CVE-2026-88801
MDJM Event Management and Mobile Events Manager <= 1.7.8.7 - -
CVE-2026-88800
MDJM Event Management and Mobile Events Manager <= 1.7.8.7 -