I want to use this citekey:
[@https://ww3.cad.de/cgi-bin/ubb/forumdisplay.cgi?action=topics&number=527]

from this bib file:

@misc{https://ww3.cad.de/cgi-bin/ubb/forumdisplay.cgi?action=topics&number=527,
  timestamp = {2017-11-15T12:28:11Z},
  title = {Foren Auf {{CAD}}.de, {{OpenFOAM}}},
  urldate = {2017-11-15},
  howpublished = {https://ww3.cad.de/cgi-bin/ubb/forumdisplay.cgi?action=topics\&number=527},
  file = {Foren auf CAD.de, OpenFOAM:/home/robin/Zotero/storage/ZZ7XAH64/forumdisplay.html:text/html}
}

but I get this failure message:
pandoc-citeproc: reference https://ww3.cad.de/cgi-bin/ubb/forumdisplay.cgi?action not found
Looks like the equal sign (=) is cutting off the remainder of the url.

But I don't know if this is a pandoc-citeproc issue, a bibtex issue, an encoding problem or something else. Maybe someone can try it?

Additional Info:
pandoc version: 1.19.2.1
panodoc-crossref version: 2.6.0
Happens from markdown to html with --standalone, default template, everything default.