  In both Run 1 and Run 2 of the LHC, the CMS collaboration has observed an
excess of events in the searches for low-mass Higgs bosons in the diphoton
final state at a mass of about 95 GeV. After a recent update of the
experimental analysis, in which the full Run 2 data collected at 13 TeV has
been included and an improved experimental calibration has been applied, the
local significance of the excess amounts to $2.9\sigma$. The presence of this
diphoton excess is especially interesting in view of a further excess observed
by CMS in ditau final states at a comparable mass and similar local
significance. Moreover, an excess of events with about $2\sigma$ local
significance and consistent with a mass of 95 GeV was observed in LEP searches
for a Higgs boson decaying to pairs of bottom quarks. We interpret the CMS
diphoton excess in combination with the ditau excess in terms of a pseudoscalar
resonance in the CP-conserving two-Higgs-doublet model (2HDM). Furthermore, we
discuss the possibility that, if CP-violation is taken into account, a CP-mixed
scalar state can in addition describe the LEP result, thus accommodating all
three excesses simultaneously. We find that the region of parameter space where
both the CMS diphoton and ditau excesses can be fitted is in tension with
current constraints from the flavour sector, potentially calling for other
new-physics contributions to flavour-physics observables, most notably $b \to
s\gamma$ transitions. We also comment on the compatibility with the recent
ATLAS di-photon searches.
