Ella Core has handover failures during concurrent Security Mode Command
Package
Affected versions
< 1.10.0
Patched versions
1.10.0
Description
Published to the GitHub Advisory Database
May 11, 2026
Reviewed
May 11, 2026
Last updated
May 11, 2026
Summary
Ella Core didn't enforce security rules on concurrent running of security procedures defined in TS 33.501 §6.9.5.1 — it could send a NAS Security Mode Command while an N2 handover was still pending (and vice versa).
Impact
Concurrent Security Mode Command and N2 handover produce a KgNB mismatch between the UE and target gNB, causing the handover to fail. Requires a stalled gNB + re-registration race to trigger.
Fix
Ella Core now enforces both rules from §6.9.5.1, blocking concurrent Security Mode Command and N2 handover procedures.
References