Masteriyo LMS <= 2.1.7 — Unauthenticated Authorization Bypass to Arbitrary Order Completion via Stripe Webhook Endpoint
CVE-2026-5167Published · Updated Action summary
Affected: ≤2.1.7Update to 2.1.8 or newer
All remediation steps- Severity
- Medium5.3
- CVSS
- 5.3CVSS 3.1 · CNA (Wordfence)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:NWhat does this vector mean?
AV:NAttack vector- Network
AC:LAttack complexity- Low
PR:NPrivileges required- None
UI:NUser interaction- None
S:UScope- Unchanged
C:NConfidentiality- None
I:LIntegrity- Low
A:NAvailability- None
- Required access
- No account needed
- Exploit prediction (EPSS)
- No score
- CISA KEV
- Not listed
On this page8
Am I affected?
Masteriyo LMS – LMS Course Builder, Quizzes & Certificates learning-management-system
- Affected≤ 2.1.7
- Patched in2.1.8
Update to 2.1.8 or newer.
You are affected if you run ≤ 2.1.7. Version 2.1.8 and later are not affected by this issue.
- Check your version: in wp-admin go to Plugins → Installed Plugins and read the version under Masteriyo LMS – LMS Course Builder, Quizzes & Certificates.
- No admin access? Run a passive check of your site. It reads public files only.
- No account is needed to exploit this. Treat any exposed site on an affected version as at risk.
What to do
- Update to version 2.1.8, or a newer patched version
- Rotate administrator passwords and application secrets if the site ran a vulnerable version while publicly reachable.
- Watch Masteriyo LMS – LMS Course Builder, Quizzes & Certificates to get an email when the next vulnerability is published.
Advisory
Source description from Wordfence Intelligence, credited to Md. Moniruzzaman Prodhan (NomanProdhan).
The Masteriyo LMS – Online Course Builder for eLearning, LMS & Education plugin for WordPress is vulnerable to Authorization Bypass Through User-Controlled Key in versions up to and including 2.1.7. This is due to insufficient webhook signature verification in the handle_webhook() function. The webhook endpoint processes unauthenticated requests and only performs signature verification if both the webhook_secret setting is configured AND the HTTP_STRIPE_SIGNATURE header is present. Since webhook_secret defaults to an empty string, the webhook processes attacker-controlled JSON payloads without any verification. This makes it possible for unauthenticated attackers to send fake Stripe webhook events with arbitrary order_id values in the metadata, mark any order as completed without payment, and gain unauthorized access to paid course content.
Exploits & references
Proof-of-concept & detection
No public proof-of-concept or detection template is known for this vulnerability.
Advisories & patches
- Advisorywordfence.com
Related CVEs
More in Masteriyo LMS – LMS Course Builder, Quizzes & Certificates
All 33| Severity | Vulnerability | CVE | Published |
|---|---|---|---|
| Medium5.3 | Unauthenticated Arbitrary Content Deletion ≤3.4.3Update to 3.5.0 | CVE-2026-116410 | |
| Medium4.3 | Authenticated (Subscriber+) Information Exposure ≤3.4.1Update to 3.4.2 | CVE-2026-82850 | |
| Medium4.3 | Authenticated (Subscriber+) Insecure Direct Object Reference ≤3.4.1Update to 3.4.2 | CVE-2026-82849 | |
| Medium4.3 | 3.4.0 - Authenticated (Custom Role+) Insecure Direct Object Reference 1.14.0 – 3.4.0Update to 3.4.1 | CVE-2026-82851 | |
| Medium6.4 | Authenticated (Custom Role+) Stored Cross-Site Scripting <3.4.1Update to 3.4.1 | CVE-2026-82847 |
- Medium5.3Unauthenticated Arbitrary Content Deletion
≤3.4.3Update to 3.5.0
- Medium4.3Authenticated (Subscriber+) Information Exposure
≤3.4.1Update to 3.4.2
- Medium4.3Authenticated (Subscriber+) Insecure Direct Object Reference
≤3.4.1Update to 3.4.2
- Medium4.33.4.0 - Authenticated (Custom Role+) Insecure Direct Object Reference
1.14.0 – 3.4.0Update to 3.4.1
- Medium6.4Authenticated (Custom Role+) Stored Cross-Site Scripting
<3.4.1Update to 3.4.1
Timeline
CVE published
Severity medium, CVSS 5.3
Record last updated
Sources & licenses
Wordfence record- Vulnerability data
- Wordfence Intelligence. Copyright 2012-2026 Defiant Inc. Licensed under the CC BY-SA 4.0.
- CVE® identifiers
- Copyright 1999-2026 The MITRE Corporation. Used under the CVE Program. CVE® is a registered trademark of The MITRE Corporation.
- CVSS / CWE
- National Vulnerability Database (NVD), shown unmodified. This product uses the NVD API but is not endorsed or certified by the NVD.
- VulnCrest content
- Summary, remediation guidance and page layout © VulnCrest. Not sourced from NVD.