CVE-2026-44317: free5GC's PCF npcf-policyauthorization POST /app-sessions panics on suppFeat=1 with missing AfRoutReq via nil pointer dereference

free5GC’s PCF POST /npcf-policyauthorization/v1/app-sessions handler panics on a single authenticated request whose ascReqData.suppFeat == "1" (enabling traffic-routing feature negotiation) and whose medComponents entries supply an afAppId but NO AfRoutReq. The create path then calls provisioningOfTrafficRoutingInfo(smPolicy, appID, routeReq, ...) with routeReq == nil and dereferences routeReq.RouteToLocs (and other fields) without a nil check, causing runtime error: invalid memory address or nil pointer dereference. Gin recovery converts the panic into HTTP 500.

The trigger is a single valid authenticated request – changing only suppFeat from "0" to "1" flips the same shape of POST from a normal 201 Created into a panic-driven 500.

This endpoint requires a valid npcf-policyauthorization OAuth2 access token (PR:L). The PCF process is not killed (Gin recovers); the realized impact is per-request panic-DoS on the app-session create path.