The free5GC UPF suffers from a lack of bounds checking on the SEID when processing PFCP Session Deletion Requests. An unauthenticated remote attacker can send a request with a very large SEID (e.g., 0xFFFFFFFFFFFFFFFF) that causes an integer conversion/underflow in LocalNode.DeleteSess() / LocalNode.Sess() when a uint64 SEID is converted to int and used in index arithmetic. This leads to a negative index into n.sess and a Go runtime panic, resulting in a denial of service (UPF crash). The issue has been reproduced on free5GC v4.1.0 with crashes observed in the session lookup/deletion path in internal/pfcp/node.go; other versions may also be affected. No authentication is required.
Fix
Nothing published yet: no patch, vendor advisory or mitigation reference on NVD, no vendor advisory in the News for this CVE, not in CISA's KEV, no fixed package version. BaselineWatch does not guess at one.
Change history 1
- First seenCVSS 7.5 · free5gcNVD modified 2026-10-13 11:10
Affected (CPE criteria) 1
cpe:2.3:a:free5gc:free5gc:4.1.0:*:*:*:*:*:*:*
References 2
- https://github.com/free5gc/free5gc/issues/731 Exploit, Issue Tracking, Third Party Advisory
- https://github.com/free5gc/free5gc/issues/731 Exploit, Issue Tracking, Third Party Advisory