Vulnerability 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 supi parameter, triggering internal URL parsing errors (net/url: invalid control character). This exposes system-level error details and can be used for service fingerprinting. All deployments of free5GC using the UDM Nudm_UEAU service may be affected. free5gc/udm pull request 75 contains a fix for the issue. No direct workaround is available at the application level. Applying the official patch is recommended.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Free5Gc | Udm | <= 1.4.1 |
Related Weaknesses (CWE)
References
- https://github.com/free5gc/free5gc/issues/749ExploitIssue TrackingVendor Advisory
- https://github.com/free5gc/free5gc/security/advisories/GHSA-h4wg-rp7m-8xx4Vendor Advisory
- https://github.com/free5gc/udm/commit/a7af2321ddea6368c43835f90f6d1b9d67dd2ea1Patch
- https://github.com/free5gc/udm/pull/75Issue TrackingPatch
FAQ
What is CVE-2026-27642?
CVE-2026-27642 is a vulnerability with a CVSS score of 7.5 (HIGH). 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 ...
How severe is CVE-2026-27642?
CVE-2026-27642 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-27642?
Check the references section above for vendor advisories and patch information. Affected products include: Free5Gc Udm.