Publishing erratum to arXiv and other best practices Is publishing a single page erratum to arXiv an acceptable practice? And does it violate the copyright of journal who published the original work?
Has the original paper been posted on the arXiv?

If so, I suggest updating it with a corrected version, and communicating clearly in the Comments field that this new version is a corrected one. (Also, I'd change the Journal-Ref to indicate that it doesn't exactly correspond to the publication.)

In terms of copyright, this may be in a grey zone in case you've signed away the rights to your preprint to the publisher. But if so, it is a grey zone academics have been comfortably treading for years.