Mukund referred me to this ticket while I was investigating RT #46290.
Initially it seemed that both this issue and RT #46290 are caused by the
same underlying problem, which is present in BIND 9.10.3-P4 (the version
reported for RT #46290) and fixed (by this ticket) in later versions.
However, I took a look at the committed fix for this ticket (commit
019132b70c3) and I believe it is broken:

    --- a/lib/dns/dispatch.c
    +++ b/lib/dns/dispatch.c
    @@ -3721,9 +3721,12 @@ dns_dispatch_importrecv(dns_dispatch_t *disp, isc_event_t *event) {
>>>         REQUIRE((disp->attributes & DNS_DISPATCHATTR_NOLISTEN) != 0);
            REQUIRE(event != NULL);
     
    -       sevent = (isc_socketevent_t *)event;
    +       if ((disp->attributes & DNS_DISPATCHATTR_NOLISTEN) == 0)
    +               return;
 
The marked REQUIRE check was supposed to be removed (cf. commit
577aecf4b7), but something seemingly went wrong.  With the REQUIRE still
in place, BIND will still crash when DNS_DISPATCHATTR_NOLISTEN is not
set and the added conditional expression will never be evaluated.

Please review the following patch:

    --- a/lib/dns/dispatch.c
    +++ b/lib/dns/dispatch.c
    @@ -3718,7 +3718,6 @@ dns_dispatch_importrecv(dns_dispatch_t *disp, isc_event_t *event) {
            isc_socketevent_t *sevent, *newsevent;
     
            REQUIRE(VALID_DISPATCH(disp));
    -       REQUIRE((disp->attributes & DNS_DISPATCHATTR_NOLISTEN) != 0);
            REQUIRE(event != NULL);
     
            if ((disp->attributes & DNS_DISPATCHATTR_NOLISTEN) == 0)

(The above should go in without a CHANGES note as it is a fix to a fix.)