Vulnerability · Published Jul 28, 2026 · Assigned by INCIBE
CVE-2026-4648Insufficient Encryption Level in CasfID Servicios Tecnológicos NFC Wristbands
Medium 6.8
In plain English
A medium-severity security flaw in NFC Wristbands from CasfID Servicios Tecnológicos. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 5% of all known vulnerabilities).
Official description
Use of an insecure cryptographic algorithm in the cashless payment system using NFC wristbands from CasfID Servicios Tecnológicos S.L.U. (version used at Resurrection Fest 2025), which employs cards based on MIFARE Classic technology (FM11RF08S). The cryptographic weakness of the authentication algorithm allows an attacker to retrieve access keys using techniques known as Backdoored Nested Attack, read the wristband’s entire contents, and clone its credentials onto a compatible rewritable card. Exploitation of this vulnerability could enable the impersonation of other attendees, the fraudulent use of the balance associated with their wristbands, and financial losses for both the affected users and the event organizers.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| CasfID Servicios Tecnológicos | NFC Wristbands | FM11RF08S variant |
Weakness: CWE-326 · Vector: CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N