6.6
MEDIUM CVSS 4.0
CVE-2026-27643
free5GC has improper error handling in NEF with information exposure
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.

INFO

Published Date :

Feb. 24, 2026, 1:16 a.m.

Last Modified :

Feb. 24, 2026, 1:16 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-27643 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 MEDIUM [email protected]
Solution
Patch the NEF component to prevent the leakage of internal parsing error details.
  • Apply the patch provided in free5gc/udr pull request 56.
  • Update free5GC UDR to a version that includes the fix.
  • Restrict access to the Nnef_PfdManagement service if possible.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-27643.

URL Resource
https://github.com/free5gc/free5gc/issues/753
https://github.com/free5gc/free5gc/security/advisories/GHSA-6468-f87j-6g82
https://github.com/free5gc/udr/commit/754d23b03755ad59077ed529ce3b971e477080c4
https://github.com/free5gc/udr/pull/56
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-27643 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-27643 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-27643 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-27643 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Feb. 24, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CWE CWE-209
    Added Reference https://github.com/free5gc/free5gc/issues/753
    Added Reference https://github.com/free5gc/free5gc/security/advisories/GHSA-6468-f87j-6g82
    Added Reference https://github.com/free5gc/udr/commit/754d23b03755ad59077ed529ce3b971e477080c4
    Added Reference https://github.com/free5gc/udr/pull/56
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 6.6
Attack Vector
Attack Complexity
Attack Requirements
Privileges Required
User Interaction
VS Confidentiality
VS Integrity
VS Availability
SS Confidentiality
SS Integrity
SS Availability