High
CVSS 7.5 Webhook Forgery Responsible Disclosure
Disclosure
Missing HMAC/Signature Across All Plugins
No cryptographic signature header on webhook callbacks across 6 e-commerce plugins; unlike Stripe/PayPal.
- Target
- European Crypto Payment Processor
- Category
- Webhook Forgery
- 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.