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.

Project Subscriptions

Vendors Products
Casfid Servicios Tecnológicos Subscribe
Nfc Wristbands Subscribe
Advisories

No advisories yet.

Fixes

Solution

Since the vulnerability stems from a hardware-level cryptographic weakness inherent in the MIFARE Classic family, it is recommended to discontinue the use of these chips (such as the FM11RF08S variant) for payment systems and critical access control systems. As a definitive solution, organizations should migrate to smart card technologies that support robust, up-to-date cryptographic standards (such as AES-128 or higher), such as the MIFARE DESFire family (EV2 or EV3).


Workaround

No workaround given by the vendor.

History

Tue, 28 Jul 2026 21:00:00 +0000

Type Values Removed Values Added
First Time appeared Casfid Servicios Tecnológicos
Casfid Servicios Tecnológicos nfc Wristbands
Vendors & Products Casfid Servicios Tecnológicos
Casfid Servicios Tecnológicos nfc Wristbands

Tue, 28 Jul 2026 16:15:00 +0000

Type Values Removed Values Added
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.
Title Insufficient Encryption Level in CasfID Servicios Tecnológicos NFC Wristbands
Weaknesses CWE-326
References
Metrics cvssV4_0

{'score': 6.8, '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'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: INCIBE

Published:

Updated: 2026-07-28T12:04:41.531Z

Reserved: 2026-03-23T12:50:31.162Z

Link: CVE-2026-4648

cve-icon Vulnrichment

Updated: 2026-07-28T12:04:38.516Z

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-07-28T20:34:49Z

Weaknesses