Vulnerability · Published Mar 22, 2026 · Assigned by VulDB

CVE-2026-4531Free5GC AMF handler.go HandleRegistrationComplete denial of service

Medium 5.3

In plain English

A medium-severity security flaw in Free5GC. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 38% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.3Medium

Exploit odds (30 days)0.4%top 62.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Go	github.com/free5gc/amf	1.4.3-0.20260306074636-52e9386401ce	GHSA-xq44-64rg-8g3h
Go	github.com/free5gc/amf	1.4.3-0.20260306074636-52e9386401ce	GO-2026-5767

Affected products (as reported)

Vendor	Product	Versions
n/a	Free5GC	4.1.0

Weakness: CWE-404 · 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

References

VDB-352319 | Free5GC AMF handler.go HandleRegistrationComplete denial of service vdb-entry, technical-description
VDB-352319 | CTI Indicators (IOB, IOC, TTP, IOA) signature, permissions-required
Submit #774073 | Linux Foundation free5GC 4.1.0 Denial of Service third-party-advisory
https://github.com/free5gc/free5gc/issues/792 issue-tracking
https://github.com/free5gc/amf/pull/198 issue-tracking, patch
https://github.com/free5gc/amf/commit/52e9386401ce56ea773c5aa587d4cdf7d53da799 patch
https://github.com/free5gc/free5gc/ product