PayTR Virtual Pos iFrame API WHMCS Module: Observable Timing Discrepancy
CVE-2026-16037 is a high-severity observable timing discrepancy vulnerability in PayTR Virtual Pos iFrame API WHMCS Module from PayTR Payment and Electronic Money Institution, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version v9.0.3 as the first without the flaw, so updating PayTR Virtual Pos iFrame API WHMCS Module to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.42% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update PayTR Virtual Pos iFrame API WHMCS Module to v9.0.3 or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| PayTR Payment and Electronic Money Institution | PayTR Virtual Pos iFrame API WHMCS Module | v9.0.0 up to, but not including, v9.0.3 | v9.0.3 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by CNA (usom.gov.tr).
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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Observable Timing Discrepancy
Two separate operations in a product require different amounts of time to complete, in a way that is observable to an actor and reveals security-relevant information about the state of the product, such as whether a particular operation was successful or not.
More Observable Timing Discrepancy vulnerabilities (CWE-208)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in PayTR Virtual Pos iFrame API WHMCS Module
- 9.1 Critical severity
- 7.5 High severity
Recent Observable Timing Discrepancy vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.4 High severity
- 8.5 High severity
- 7.5 High severity
- 8.3 High severity
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