Critical
CVSS 9.1 Broken Authentication Responsible Disclosure
Disclosure
Unauthenticated Mass User Data Leak via Chat Messages Endpoint
Finding 7: Unauthenticated Mass User Data Leak via Chat Messages Endpoint Severity: Critical (CVSS 9.1 - AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N) The `/api/messages/` endpoint returns 1,000 chat messages from 492 unique users without ANY authentication. Each message includes the user
- Target
- NA Online Casino
- Category
- Broken Authentication
- Channel
- Responsible Disclosure
- Disclosed
- 2026-03
Redaction note
Vendor identity withheld.
This finding is documented here as part of MemCyber’s public disclosure record. The vendor has been anonymized to a sector and region descriptor. Full technical detail — including root cause, reproducible proof-of-concept, remediation guidance, and vendor attribution where granted — is available to qualified prospects under NDA.
Coordinated disclosure
How we handled it.
- Reported to the vendor via Responsible Disclosure with a reproducible proof-of-concept.
- Triage + remediation window coordinated with the vendor security team.
- Fix verified before any public reference.
- This record published only after the embargo period closed.