CVE-2026-4648Insufficient Encryption Level in CasfID Servicios Tecnológicos NFC Wristbands
- 6.8MediumCVSS base score
- 0.16%Exploitation in 30 daysEPSS · top 95% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By INCIBE
- 4 months later
· 4 months later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| INCIBECNA (assigner) | 4.0 | Medium6.8 | 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 |
| NVDNVD · Deferred | 4.0 | Medium6.8 | 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 (exploitation in 30 days)
- 0.16% · top 95% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.8.
Affected products
CasfID Servicios Tecnológicos · NFC Wristbands
- affected FM11RF08S variant
What to do
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).
References
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-49765 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-4648)Record last updated .