CVE-2026-25501: free5GC SMF crash (nil pointer dereference) on PFCP SessionReportRequest when ReportType.DLDR is set but DownlinkDataReport IE is missing
free5GC SMF provides Session Management Function for free5GC, an open-source project for 5th generation (5G) mobile core networks. In versions up to and including 1.4.1, SMF panics due to nil pointer dereference and the SMF process terminates. This is triggered by a malformed PFCP SessionReportRequest on the SMF PFCP (UDP/8805) interface. No known upstream fix is available, but some workarounds are available. ACL/firewall the PFCP interface so only trusted UPF IPs can reach SMF (reduce spoofing/abuse surface); drop/inspect malformed PFCP SessionReportRequest messages at the network edge where feasible, and/or add recover() around PFCP handler dispatch to avoid whole-process termination (mitigation only).
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-25501?
CVE-2026-25501 has been classified as a high severity vulnerability due to its potential to crash the free5GC SMF.
How do I fix CVE-2026-25501?
To fix CVE-2026-25501, upgrade free5GC to version 1.4.2 or later, which resolves the nil pointer dereference issue.
Which versions of free5GC are affected by CVE-2026-25501?
CVE-2026-25501 affects free5GC versions up to and including 1.4.1.
What components of free5GC are impacted by CVE-2026-25501?
CVE-2026-25501 specifically impacts the Session Management Function (SMF) component of free5GC.
What causes the crash in CVE-2026-25501?
The crash in CVE-2026-25501 is caused by a nil pointer dereference during the processing of a PFCP SessionReportRequest when critical information is missing.