Are there other, perhaps special situation, where such a Catholic - divorced and remarried - may be allowed to receive the Eucharist?
No there aren't
Unless a declaration of nullity [cf.entire Ch 1 (Art 1-7) Code of Canon Law] is issued on the prior marriage, and the current marriage convalidated.
a. Epikeia and aequitas canonica exist in the sphere of human and
purely ecclesiastical norms of great significance, but cannot be
applied to those norms over which the Church has no discretionary
authority. The indissoluble nature of marriage is one of these norms
which goes back to Christ Himself and is thus identified as a norm of
divine law. The Church cannot sanction pastoral practices - for
example, sacramental pastoral practices - which contradict the clear
instruction of the Lord.
In other words, if the prior marriage of two divorced and remarried members of the faithful was valid, under no circumstances can their
new union be considered lawful and therefore reception of the
sacraments is intrinsically impossible. The conscience of the
individual is bound to this norm without exception.2
2 Cf. Angel Rodríguez Luño, L’epicheia nella cura pastorale
dei fedeli divorziati risposati, ibid., pp. 75-87; Piero Giorgio
Marcuzzi, S.D.B., Applicazione di "aequitas et epikeia" ai contenuti
della Lettera della Congregazione per la Dottrina della Fede del 14
settembre 1994, ibid., pp. 88-98; Gilles Pelland, S.J., La pratica
della Chiesa antica relativa ai fedeli divorziati risposati, ibid.,
Source: Objections to the Church's Teaching on the Reception of Holy Communion by Divorced and Remarried Members of the Faithful by Joseph Cardinal Ratzinger | Congregation for the Doctrine for the Faith.
Please see also
CCC 1665 The remarriage of persons divorced from a living, lawful
spouse contravenes the plan and law of God as taught by Christ. They
are not separated from the Church, but they cannot receive Eucharistic
communion. They will lead Christian lives especially by educating
their children in the faith.
CDF October 22, 2014 response to the Question of a French Priest: "Can a confessor grant absolution to a penitent who, having been religiously married, has contracted a second union following divorce?"
- OP contained - "civilly" re-married Catholic - wording. If one is re-married, there must have been a prior marriage that ended in a divorce.
- A Sacramental marriage is a marriage between two baptized persons. A valid marriage between a Catholic and a non-baptized person is NOT a sacramental marriage.
- If a Catholic marries not observing the Church's laws on marriage, that marriage is invalid.
Please see this answer to: Is a Catholic annulment divorce in a Catholic way?