Vulnerability · Published Sep 8, 2026 · Assigned by TR-CERT
CVE-2026-16037Callback Authentication Bypass via Timing Attack in PayTR's PayTR Virtual Pos iFrame API WHMCS Module
High 7.5
In plain English
A high-severity security flaw in PayTR Virtual Pos iFrame API WHMCS Module from PayTR Payment and Electronic Money Institution Inc.. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 36% of all known vulnerabilities).
Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.4%top 63.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Observable timing discrepancy vulnerability in PayTR Payment and Electronic Money Institution Inc. PayTR Virtual Pos iFrame API WHMCS Module allows Black Box Reverse Engineering. This issue affects PayTR Virtual Pos iFrame API WHMCS Module: from v9.0.0 before v9.0.3.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| PayTR Payment and Electronic Money Institution Inc. | PayTR Virtual Pos iFrame API WHMCS Module | v9.0.0 – before v9.0.3 |
Weakness: CWE-208 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
References
- https://siberguvenlik.gov.tr/guvenlik-bildirimleri/detay/tr-26-1034 government-resource