3GPP 24.501 v20.0.0 — the document's own text
D.8.8 Messages with semantically incorrect contents
Taught in 5. Finding your way around TS 24.501 (CT1 — the group that writes what your phone says, in depth), 4. Inside TS 24.501, the document at the centre (CT1 — the group that writes what your phone says, overview).
When a message with semantically incorrect contents is received, the UE shall perform the foreseen reactions of the procedural part of clauses D.2. If, however no such reactions are specified, the UE shall ignore the message.
The network should follow the same procedure.