Vulnerability · Published Feb 23, 2026 · Assigned by GitHub_M

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

Medium 6.6

In plain English

A medium-severity improper input validation in udm from free5gc. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 44% of all known vulnerabilities).

Severity (CVSS 4.0)6.6Medium
Exploit odds (30 days)0.5%top 55.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

VendorProductVersions
free5gc udm <= 1.4.1

Weakness: CWE-20 · 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

References