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

Vulnerability summary

CVE-2025-69251 is a medium (CVSS 6.6) Improper Input Validation vulnerability in free5gc udm. EPSS estimates a 0.52% chance of exploitation in the next 30 days, higher than 43.3% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 23-02-2026
   PublishedVulnerability first disclosed.
2. 25-02-2026
   Last modifiedVulnerability information updated.

Description

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.

• CWE-20Improper Input ValidationThe product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.