In November 2025, BDO Cyber Security GmbH participated in the “5G Hackathon” organized by the German Federal Office for Information Security (BSI) in Freital. As part of the event, selected expert teams were granted exclusive access to carrier-grade 5G Standalone mobile network systems within the laboratory environments of the German Federal Office for Information Security (TEMIS).

The objective of the hackathon was to assess the security of real-world 5G network infrastructures under realistic operating conditions and to identify potential vulnerabilities in order to further strengthen the resilience of modern mobile networks. The BDO Cyber Security GmbH team conducted targeted analyses and fuzzing activities on the PFCP (Packet Forwarding Control Protocol), a key control protocol in 5G networks.

During these investigations, our team identified three previously unknown vulnerabilities. By sending various malformed data packets, it was possible to crash a component of the packet core gateway in three different ways. As the affected component automatically restarts, service availability is only impacted for as long as the malicious packets continue to be transmitted. Since the affected component is typically not publicly accessible and can only be reached from within the 5G core network, each vulnerability was assigned a medium severity rating (CVSS v3.1 Base Score: 6.5).

These findings were responsibly disclosed as part of the 5G hackathon to the affected vendor, Ericsson, which published a corresponding Security Advisory in June 2026. In addition, Ericsson has released an update for the Packet Core Gateway (PCG); the identified vulnerabilities have been remediated as of version 1.30. As a result, the relevant information is now publicly available and can be leveraged by network operators and security professionals to further strengthen the security of their systems.

The publication underscores the importance of independent security analyses in modern mobile network infrastructures and highlights the value of applied, real-world research conducted in formats such as the BSI 5G Hackathon, whose execution and the publication of results were explicitly requested and actively supported by the participating vendors.

Further CVEs and security advisories published by our team can be found on our advisory overview page.

If you require support in identifying or remediating vulnerabilities in systems, applications, or IoT devices, we would be pleased to assist you. Our offensive security services include penetration testing and red team engagements designed to help you stay one step ahead of potential attackers. In addition, we provide a comprehensive range of consulting services that further complement our portfolio.

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