Insufficient Encryption Level in CasfID Servicios Tecnológicos NFC Wristbands
Summary
| CVE | CVE-2026-4648 |
|---|---|
| State | PUBLISHED |
| Assigner | INCIBE |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-28 12:16:36 UTC |
| Updated | 2026-10-24 13:10:00 UTC |
| 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. |
Risk And Classification
Primary CVSS: v4.0 6.8 MEDIUM from [email protected]
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS: 0.001180000 probability, percentile 0.020320000 (date 2026-07-29)
Problem Types: CWE-326 | CWE-326 CWE-326: Inadequate Encryption Strength
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 6.8 | MEDIUM | 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/E:X/C... |
| 4.0 | CNA | CVSS | 6.8 | MEDIUM | 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 |
CVSS v4.0 Breakdown
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | CasfID Servicios Tecnolgicos | NFC Wristbands | affected FM11RF08S variant custom | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.incibe.es/en/incibe-cert/notices/aviso/insufficient-encryption-level-ca... | [email protected] | www.incibe.es | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Luis Miranda Acebedo (en)
Additional Advisory Data
Solutions
CNA: 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).