CVE-2026-4648

What it is

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.

At a glance

Exploitability

Can be exploited with physical access without logging in. High risk of data exposure, data tampering.

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

1. 2026-07-28 12:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-24 13:10 UTC Last updatedMost recent change to the record

Details

Published

2026-07-28 12:16 UTC

Last modified

2026-10-24 13:10 UTC

Exploit probability

0.2% · EPSS, next 30 days

Weakness

CWE-326 · Inadequate encryption strength

Record status

Deferred

Attack profile CVSS 4.0 · 6.8

Attack vector

Physical

Complexity

Low

Attack requirements

None

Privileges needed

None

User interaction

None

Confidentiality

High

Integrity

High

Availability

None