Unauthenticated order completion via unsigned Stripe webhooks
Published Apr 8, 2026 · Updated Apr 8, 2026
Authorization bypass in ThemeGrill Masteriyo LMS 2.1.7 and earlier allows remote attackers to complete unpaid orders through Stripe webhooks. The handle_webhook() function verifies signatures only when both a configured webhook_secret and HTTP_STRIPE_SIGNATURE are present, so the default empty secret permits attacker-controlled JSON. No account is required; a forged event can supply an arbitrary order_id, mark that order completed without payment, and unlock its paid course content.
Summary
What happened
Authorization bypass in ThemeGrill Masteriyo LMS 2.1.7 and earlier allows remote attackers to complete unpaid orders through Stripe webhooks. The handle_webhook() function verifies signatures only when both a configured webhook_secret and HTTP_STRIPE_SIGNATURE are present, so the default empty secret permits attacker-controlled JSON. No account is required; a forged event can supply an arbitrary order_id, mark that order completed without payment, and unlock its paid course content.
The record
- CVE
- CVE-2026-5167
- Published
- Apr 8, 2026
- Updated
- Apr 8, 2026
- Vendor
- ThemeGrill
- Product
- Masteriyo LMS
- Classifications
- CWE-639, T1190, T1565.001
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 8, 2026CVE publishedPublication date reported by the CVE source.
- Apr 8, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <=2.1.7
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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