Is there an upper limit to temperature in the universe?

Question

The Sun's core temperature has been modelled to be $\approx 1.57 \times 10^7$ K

In supernovae:

"In lower mass cores the collapse is stopped and the newly formed neutron core has an initial temperature of about 100 billion kelvin, 6,000 times the temperature of the sun's core. At this temperature, neutrino-antineutrino pairs of all flavours are efficiently formed by thermal emission." (1)

Also:

"[In supernovae] the core temperature rises to over 100 billion degrees as the iron atoms are crushed together." (2)

Question: Does temperature in the universe have an upper limit, like the lower limit of absolute zero? What’s the highest temperature possible in the universe?

References:

(1) https://en.wikipedia.org/wiki/Supernova

(2) https://imagine.gsfc.nasa.gov/science/objects/supernovae1.html

Answer 1

The highest temperatures in the universe are at the center of black holes, but we don't have a theory which describes what happens at the singularity, so nobody knows if the temperature there is finite or infinite.