CVE-2026-4648: Weak Crypto

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.

Is your site exposed to CVE-2026-4648?

Run a free security scan — no signup, results in seconds.

Weakness Type (CWE)

CWE-326 CWE-326

References

Other References

https://www.incibe.es/en/incibe-cert/notices/aviso/insufficient-encryption-level-casfid-servicios-tecnologicos-nfc

Frequently Asked Questions

What is CVE-2026-4648? +

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.

How do I check if I'm vulnerable to CVE-2026-4648? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2024-13026

A vulnerability exists in Algo Edge up to 2.1.1 - a previously used (legacy) component of navify® Algorithm Suite. The …

CVE-2025-2516

The use of a weak cryptographic key pair in the signature verification process in WPS Office (Kingsoft) on Windows allows …

CVE-2025-46833

Programs/P73_SimplePythonEncryption.py illustrates a simple Python encryption example using the RSA Algorithm. In versions prior to commit 6ce60b1, an attacker may …

CVE-2024-21881

Inadequate Encryption Strength vulnerability allow an authenticated attacker to execute arbitrary OS Commands via encrypted package upload.This issue affects Envoy: …

CVE-2026-49852

joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. Prior to …

CVE-2026-44523 10.0

Note Mark is an open-source note-taking application. Prior to 0.19.4, no minimum length or entropy is enforced on the JWT_SECRET …

CVE-2026-4648