CVE-2026-33661: yansongda pay · Authentication Bypass by Spoofing
Affects yansongda paySource CVE Database V5
Not known to be exploited · CVSS 8.6 High : upgrade to 3.7.20 soon.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 44% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 3.7.20
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 26 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade pay and yansongda/pay to 3.7.20.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| yansongdapay | Affected
| Fixed in
|
GitHubyansongda/paypkg:github/yansongda/payOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade yansongda pay to version 3.7.20 or later, where the verify_wechat_sign() function properly enforces signature verification regardless of the Host header. No other mitigations are indicated by the vendor advisory. Patch status is confirmed fixed in version 3.7.20.
Description
CVE-2026-33661 is an authentication bypass vulnerability in the yansongda pay SDK prior to version 3.7.20. The vulnerability arises because the verify_wechat_sign() function skips signature verification if the HTTP request's Host header is set to 'localhost'. This allows an attacker to forge WeChat Pay payment success notifications by sending a crafted request with a 'Host: localhost' header, causing applications to incorrectly mark orders as paid. The issue is fixed in version 3.7.20.