# CVE-2026-30062: free5gc NGAP handler denial of service via malformed NAS PDU

Source: https://junglewise.ai/threats/cve-2026-30062-free5gc-ngap-handler-denial-of-service-via-malformed-nas-pdu  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-27. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-30062 · Severity: high · CVSS 7.5 · Published 2026-08-27

free5gc is an open-source 5G core network implementation used in mobile network deployments. The Access and Mobility Management Function (AMF) component can be crashed remotely when it receives a malformed network message containing an invalid NAS Protocol Data Unit (PDU). An attacker with network access to the 5G core can cause service unavailability by sending a specially crafted message that triggers an unhandled crash, disrupting mobile network operations.

Technologies: [free5GC](https://junglewise.ai/threats/technologies/free5gc). Vendors: [free5GC](https://junglewise.ai/threats/vendors/free5gc).

## Quick answers

**Is CVE-2026-30062 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-30062 being exploited in the wild.

**How severe is CVE-2026-30062?** High severity, with a CVSS score of 7.5, published 27 August 2026.

**Which products and versions are affected?** free5GC v4.0.1.

**Is there a fix for CVE-2026-30062?** 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-2026-30062 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-30062?** Check whether you run free5GC 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 vulnerability is an unvalidated input issue in the NGAP handler's NAS PDU processing layer. When the AMF receives an InitialUEMessage containing a malformed NAS PDU (e.g., a single byte instead of a properly formed message), the nas.GetSecurityHeaderType() function attempts to access an array index that exceeds the actual data length, causing a panic and immediate process termination. The attack requires network connectivity to the NGAP interface (SCTP port) and no authentication. The vulnerability affects free5gc v4.0.1 and likely earlier versions; patches addressing input validation should be available in newer versions.

## Affected products

- free5gc free5gc v4.0.1

## Timeline

- 2026-01-18: disclosed: Issue reported on GitHub
- 2026-08-27: advisory: CVE-2026-30062 published

## References

- [https://github.com/free5gc/free5gc/issues/812](https://github.com/free5gc/free5gc/issues/812)

## Related threats

- [Free5GC SMF resource exhaustion in PFCP session establishment](https://junglewise.ai/threats/cve-2026-106805-a-resource-exhaustion-issue-exists-in-free5gc-v4-2-3-during-pfcp)
- [Free5GC race condition in GMM handler RanUe context access](https://junglewise.ai/threats/cve-2026-94043-a-vulnerability-was-determined-in-free5gc-up-to-4-2-3-this)
- [Free5GC UPF nil pointer dereference in PFCP Session Report](https://junglewise.ai/threats/cve-2026-75439-free5gc-upf-nil-pointer-dereference-in-pfcp-session-report)
- [free5GC NRF input validation bypass in NF profile registration](https://junglewise.ai/threats/cve-2026-55068-free5gc-nrf-input-validation-bypass-in-nf-profile-registration)
- [free5gc NSSF nil pointer dereference in NssaiAvailabilitySubscriptionCreate](https://junglewise.ai/threats/cve-2026-30073-free5gc-nssf-nil-pointer-dereference-in)