CVE-2026-33661

Published: Mar 26, 2026 Last Modified: Mar 27, 2026
ExploitDB:
Other exploit source:
Google Dorks:
HIGH 8,6
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Scope: changed
Confidentiality: none
Integrity: high
Availability: none

Description

AI Translation Available

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.

EPSS (Exploit Prediction Scoring System)

Trend Analysis

EPSS (Exploit Prediction Scoring System)

Prevede la probabilità di sfruttamento basata su intelligence sulle minacce e sulle caratteristiche della vulnerabilità.

EPSS Score
0,0013
Percentile
0,3th
Updated

Single Data Point

Only one EPSS measurement is available for this CVE. Trend analysis requires multiple data points over time.

290

Authentication Bypass by Spoofing

Incomplete
Common Consequences
Security Scopes Affected:
Access Control
Potential Impacts:
Bypass Protection Mechanism Gain Privileges Or Assume Identity
Applicable Platforms
All platforms may be affected
View CWE Details
https://github.com/yansongda/pay/security/advisories/GHSA-q938-ghwv-8gvc
https://github.com/yansongda/pay/commit/26987ebf789f1e7f0a85febb640986ab4289fd7f
https://github.com/yansongda/pay/releases/tag/v3.7.20
https://github.com/yansongda/pay/security/advisories/GHSA-q938-ghwv-8gvc