Pay is an open-source payment SDK extension package for various Chinese payment services. Prior to version 3.7.20, the `verify_wechat_sign()` function in `src/Functions.php` unconditionally skips all signature verification when the PSR-7 request reports `localhost` as the host. An attacker can exploit this by sending a crafted HTTP request to the WeChat Pay callback endpoint with a `Host: localhost` header, bypassing the RSA signature check entirely. This allows forging fake WeChat Pay payment success notifications, potentially causing applications to mark orders as paid without actual payment. Version 3.7.20 fixes the issue.
References
Configurations
No configuration.
History
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Information
Published : 2026-03-26 22:16
Updated : 2026-03-30 13:26
NVD link : CVE-2026-33661
Mitre link : CVE-2026-33661
CVE.ORG link : CVE-2026-33661
JSON object : View
Products Affected
No product.
CWE
CWE-290
Authentication Bypass by Spoofing
