CVE-20XX-?
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CVE-2026-33661

8.6 HIGH 0.5% exploit odds Fix listed Other Web app

What it is

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.

At a glance

Exploitability
Can be exploited over the network without logging in. High risk of data tampering.
Exploit odds
0.5% chance of exploitation in the next 30 days (EPSS).
Fix
A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

  1. PublishedDisclosed publicly on CVE.org and NVD
  2. Last updatedMost recent change to the record

Why it ranks here

Details

Published
Last modified
Exploit probability
0.5% · EPSS, next 30 days
Weakness
CWE-290
Record status
Analyzed

Affected

Attack profile CVSS 3.1 · 8.6

Attack vector
Network
Complexity
Low
Privileges needed
None
User interaction
None
Scope
Changed
Confidentiality
None
Integrity
High
Availability
None
Raw vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-33661.md and follow it. Check whether this project is affected by CVE-2026-33661. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record