CVE-2025-69251 MEDIUM

CVE-2025-69251: free5GC has Improper Input Validation in UDM, Leading to Information Exposure

Vendor Free5Gc
Product udm
Weakness CWE-20 · Input validation
Published February 23, 2026
Last update February 25, 2026

CVSS base score

6.6/10
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:U

What the vulnerability does

01Description

free5gc UDM provides Unified Data Management (UDM) for free5GC, an open-source project for 5th generation (5G) mobile core networks. In versions up to and including 1.4.1, remote attackers can inject control characters (e.g., %00) into the ueId parameter, triggering internal URL parsing errors (net/url: invalid control character). This exposes system implementation details and can aid in service fingerprinting. All deployments of free5GC using the UDM Nudm_UECM service may be affected. free5gc/udm pull request 76 contains a fix for the issue. No direct workaround is available at the application level. Applying the official patch is recommended.

Key dates

02Disclosure timeline

February 23, 2026 CVE published
February 25, 2026 Record updated