cvedb.io
CVE-2026-33661
HIGH · CVSS 8.6
EPSS exploitation probability: 0%
Published 2026-03-26T22:16:29.560 · Last modified 2026-06-17T10:37:52.897

Summary

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.

Affected products

yansongda — pay

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.