A Three-Agent LLM Pipeline Finds 84 Flaws in 4G and 5G Core Software, 23 Still Unfixed

Open-source 4G and 5G core network implementations including OpenAirInterface, eUPF, Open5GS, SD-Core, and free5GC, plus two unnamed commercial 5G cores

Researchers at Nanyang Technological University in Singapore built iFinder, a multi-agent system that chains three LLM agents: one scans for unchecked use of data from incoming messages, one consults 3GPP standards documentation to determine whether validation happens elsewhere in the flow, and one generates working exploits, tests them against live networks, reads the logs, and iterates until it succeeds or fails. The pipeline found 84 previously unknown vulnerabilities. Developers confirmed 83, 81 carry CVE numbers, 58 are patched, and 23 confirmed CVEs remain unfixed. The most serious, CVE-2026-8233, lets an attacker with access to an internal mobile-core interface hijack a subscriber's data session and redirect that subscriber's outbound traffic to attacker-controlled infrastructure; it was validated on two commercial 5G cores, including a reproduction inside a partner vendor's lab under default settings. Three exploits transferred from open-source to commercial systems, indicating shared architectural weaknesses. On a benchmark of known flaws iFinder detected 15 of 22, a 68% rate, with roughly 25% false positives. Response varied by project: Open5GS, SD-Core, and free5GC engaged and patched, eUPF acknowledged but cited resource constraints, and OpenAirInterface did not respond

Missing validation of fields in messages arriving over internal mobile-core interfaces, in a stack whose security model assumes those interfaces are trusted. In the session-hijacking case the network reuses forwarding rule identifiers without checking uniqueness. The disclosure asymmetry is the operational problem: an automated pipeline produced 84 findings, and 23 confirmed CVEs sit unpatched because remediation capacity did not scale with discovery