Unauthenticated payment bypass via untrusted PayPal IPN validation
Published Jul 11, 2026 · Updated Jul 11, 2026
Payment-authenticity failure in ThimPress WP Hotel Booking 2.3.1 and earlier allows remote attackers to mark bookings as paid. The web_hook_process_paypal_standard() handler trusts the request-controlled test_ipn flag to choose PayPal's sandbox endpoint, completes pending transactions, and omits receiver, currency, and transaction-uniqueness checks after VERIFIED. No site credentials or special configuration are required; a free PayPal sandbox account or replayed verified IPN can falsely complete a booking without merchant payment.
Summary
What happened
Payment-authenticity failure in ThimPress WP Hotel Booking 2.3.1 and earlier allows remote attackers to mark bookings as paid. The web_hook_process_paypal_standard() handler trusts the request-controlled test_ipn flag to choose PayPal's sandbox endpoint, completes pending transactions, and omits receiver, currency, and transaction-uniqueness checks after VERIFIED. No site credentials or special configuration are required; a free PayPal sandbox account or replayed verified IPN can falsely complete a booking without merchant payment.
The record
- CVE
- CVE-2026-11901
- Published
- Jul 11, 2026
- Updated
- Jul 11, 2026
- Vendor
- Overdrive Eletrônica
- Product
- WP Hotel Booking
- Classifications
- CWE-345, T1565.003
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 11, 2026CVE publishedPublication date reported by the CVE source.
- Jul 11, 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 <=2.3.1
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
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Technologies
Your stack
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Your stack
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