Is CVE-2026-42081 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-42081 being exploited in the wild.

How severe is CVE-2026-42081?

Medium severity, with a CVSS score of 6.1, published 27 May 2026.

Which products and versions are affected?

github.com/free5gc/amf (Go) <= 1.4.3, SEMVER:introduced=0, SEMVER:introduced=0,last_affected=1.4.3.

Is there a fix for CVE-2026-42081?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-42081 attacked?

It is attacked from the adjacent network, in a software library.

Am I affected by CVE-2026-42081?

Check whether you run github.com/free5gc/amf (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-42081: free5GC AMF improper security check in NGAP PathSwitchRequest

Q: Is there a fix for CVE-2026-42081?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

Q: How is CVE-2026-42081 attacked?

It is attacked from the adjacent network, in a software library.

Q: Am I affected by CVE-2026-42081?

Check whether you run github.com/free5gc/amf (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-42081 · Severity: medium · CVSS 6.1 · Published 2026-05-27

A vulnerability in the Free5GC Access and Mobility Management Function (AMF) allows a compromised or untrusted base station to disrupt mobile service for specific users. By sending a specially crafted network request, an attacker can corrupt the security settings stored for a mobile device, causing all future connection handovers to fail. This results in a persistent loss of cellular connectivity for the affected user until they manually re-register with the network.

Technologies: github.com/free5gc/amf (Go). Vendors: Go.

Quick answers

Is CVE-2026-42081 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-42081 being exploited in the wild.
How severe is CVE-2026-42081?: Medium severity, with a CVSS score of 6.1, published 27 May 2026.
Which products and versions are affected?: github.com/free5gc/amf (Go) <= 1.4.3, SEMVER:introduced=0, SEMVER:introduced=0,last_affected=1.4.3.
Is there a fix for CVE-2026-42081?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-42081 attacked?: It is attacked from the adjacent network, in a software library.
Am I affected by CVE-2026-42081?: Check whether you run github.com/free5gc/amf (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The Access and Mobility Management Function (AMF) in Free5GC (v1.4.3 and earlier) fails to implement the verification requirements of 3GPP TS 33.501 §6.7.3.1. Specifically, the 'handlePathSwitchRequestMain' function in 'amf/internal/ngap/handler.go' unconditionally overwrites locally stored User Equipment (UE) Security Capabilities with values provided in an NGAP PathSwitchRequest message from a gNB. An attacker controlling a gNB can send a PathSwitchRequest with null or unsupported integrity/encryption algorithms. The AMF then propagates these corrupted capabilities to target gNBs in subsequent Handover Request messages, leading to mandatory handover rejections per TS 38.413 and resulting in a persistent DoS for the affected UE.

Affected products

free5gc amf <= 1.4.3

Identifiers

CVE-2026-42081
GHSA-77x9-rf64-92gv
GO-2026-5209

Timeline

2026-05-07: advisory: GitHub Advisory GHSA-77x9-rf64-92gv published
2026-05-27: disclosed: NVD publication of CVE-2026-42081

References

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