Description
A weakness has been identified in Free5GC 4.1.0. Affected is the function HandleRegistrationComplete of the file internal/gmm/handler.go of the component AMF. Executing a manipulation can lead to denial of service. The attack may be performed from remote. This patch is called 52e9386401ce56ea773c5aa587d4cdf7d53da799. It is best practice to apply a patch to resolve this issue.
Published: 2026-03-22
Score: 6.9 Medium
EPSS: < 1% Very Low
KEV: No
Impact: Denial of Service
Action: Patch Now
AI Analysis

Impact

The identified weakness resides in the HandleRegistrationComplete function within the AMF component of Free5GC version 4.1.0. A crafted request can trigger a denial of service, causing the AMF to stop responding to additional registration requests. This behavior is classified under CWE-404: Unhandled Resource Conflict. The vulnerability allows a remote attacker to disrupt service availability for the affected network functions.

Affected Systems

The CVE targets the Free5GC open‑source network function suite, specifically the AMF (Access and Mobility Management Function). The vulnerable code appears only in release 4.1.0. Systems running this exact version are at risk; later releases should be examined for the patch but are not explicitly listed as affected by this report.

Risk and Exploitability

The CVSS score of 6.9 indicates a medium severity impact with remote exploitation potential. EPSS is not available, so the exploitation probability cannot be quantified. The vulnerability is not recorded in CISA’s KEV catalogue, implying no widespread public exploits are currently documented. Nevertheless, because the attack can be launched remotely and may cause service interruptions, administrators should consider the risk high enough to prioritize remediation.

Generated by OpenCVE AI on March 22, 2026 at 02:21 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Apply the patch referenced in commit 52e9386401ce56ea773c5aa587d4cdf7d53da799 to the AMF component
  • Upgrade to the latest Free5GC release, ensuring it contains the AMF mitigation
  • Verify that the AMF service processes registration requests normally after the patch
  • Monitor AMF logs for any repeated registration requests that could indicate an attempt to trigger a denial of service

Generated by OpenCVE AI on March 22, 2026 at 02:21 UTC.

Tracking

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-xq44-64rg-8g3h Free5GC AMF is vulnerable to DoS through its HandleRegistrationComplete function
History

Mon, 23 Mar 2026 16:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Sun, 22 Mar 2026 01:45:00 +0000

Type Values Removed Values Added
Description A weakness has been identified in Free5GC 4.1.0. Affected is the function HandleRegistrationComplete of the file internal/gmm/handler.go of the component AMF. Executing a manipulation can lead to denial of service. The attack may be performed from remote. This patch is called 52e9386401ce56ea773c5aa587d4cdf7d53da799. It is best practice to apply a patch to resolve this issue.
Title Free5GC AMF handler.go HandleRegistrationComplete denial of service
First Time appeared Free5gc
Free5gc free5gc
Weaknesses CWE-404
CPEs cpe:2.3:a:free5gc:free5gc:*:*:*:*:*:*:*:*
Vendors & Products Free5gc
Free5gc free5gc
References
Metrics cvssV2_0

{'score': 5, 'vector': 'AV:N/AC:L/Au:N/C:N/I:N/A:P/E:ND/RL:OF/RC:C'}

cvssV3_0

{'score': 5.3, 'vector': 'CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:X/RL:O/RC:C'}

cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:X/RL:O/RC:C'}

cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X'}

Subscriptions

Free5gc Free5gc
cve-icon MITRE

Status: PUBLISHED

Assigner: VulDB

Published:

Updated: 2026-03-23T15:34:56.907Z

Reserved: 2026-03-21T07:47:21.184Z

Link: CVE-2026-4531

cve-icon Vulnrichment

Updated: 2026-03-23T15:34:42.697Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-03-22T02:15:59.270

Modified: 2026-03-23T16:16:51.980

Link: CVE-2026-4531

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-03-25T14:46:49Z

Weaknesses