CVE-2026-27643 Details
Description
free5GC UDR is the user data repository (UDR) for free5GC, an an open-source project for 5th generation (5G) mobile core networks. In versions up to and including 1.4.1, the NEF component reliably leaks internal parsing error details (e.g., invalid character 'n' after top-level value) to remote clients, which can aid attackers in service fingerprinting. All deployments of free5GC using the Nnef_PfdManagement service may be affected. free5gc/udr pull request 56 contains a patch for the issue. There is no direct workaround at the application level. The recommendation is to apply the provided patch.
An improper error handling vulnerability has been identified in the free5GC User Data Repository (UDR) component, specifically within the NEF (Network Exposure Function) service. This vulnerability is present in free5GC versions through 1.4.1. When the Nnef_PfdManagement service is used and a requested application PFD (Policy Framework Data) is not found, the NEF component incorrectly returns a 500 Internal Server Error. This response includes internal parsing error details, such as 'invalid character 'n' after top-level value', which can assist attackers in service fingerprinting. The issue arises because NEF fails to properly handle non-existent app IDs, instead of mapping the error to a suitable 4xx client error, such as 404 Not Found.
The vulnerability has been patched in free5GC UDR version 1.4.1. Users should upgrade to this version. The patch is also available in the free5GC UDR GitHub repository, in pull request #56.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Feb 26, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/free5gc/free5gc/issues/753 | [email protected] | ExploitIssue TrackingPatchVendor Advisory |
| https://github.com/free5gc/free5gc/security/advisories/GHSA-6468-f87j-6g82 | [email protected] | PatchVendor Advisory |
| https://github.com/free5gc/udr/commit/754d23b03755ad59077ed529ce3b971e477080c4 | [email protected] | Patch |
| https://github.com/free5gc/udr/pull/56 | [email protected] | Issue TrackingPatch |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-209 | Generation of Error Message Containing Sensitive Information | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| free5gc udr | <= 1.4.1 |
CPE
Remediation
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Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Feb 25, 2026 | Initial Analysis | [email protected] |
| Feb 24, 2026 | New CVE Received | [email protected] |