CVE-2026-42459 HIGH

CVE-2026-42459: free5GC: Improper Input Validation and Generation of Error Message Containing Sensitive Information in github.com/free5gc/udm

Vendor Free5Gc
Product free5gc
Weakness CWE-20 · Input validation
Published May 27, 2026
Last update May 28, 2026

CVSS base score

7.7/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P

What the vulnerability does

01Description

free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, the free5GC UDM component fails to validate the supi path parameter in six GET handlers of the nudm-sdm (Subscriber Data Management) service. An unauthenticated attacker can inject control characters into the SUPI parameter, causing UDM to forward a malformed request to UDR and return a 500 Internal Server Error response that exposes internal infrastructure details. This vulnerability is fixed in 4.2.2.

Key dates

02Disclosure timeline

May 27, 2026 CVE published
May 28, 2026 Record updated