What is our policy vis-a-vie bug priorities?

JIRA makes it fairly clear:

Blocks development and/or testing work, production could not run
Crashes, loss of data, severe memory leak.
Major loss of function.
Minor loss of function, or other problem where easy workaround is present.
Cosmetic problem like misspelt words or misaligned text.

 I's guess it would be major or perhaps minor depending on your point of view.