USN-5821-3: pip regression

USN-5821-3: pip regression

USN-5821-1 fixed a vulnerability in wheel and pip. Unfortunately,
it was missing a commit to fix it properly in pip.

We apologize for the inconvenience.

Original advisory details:

Sebastian Chnelik discovered that wheel incorrectly handled
certain file names when validated against a regex expression.
An attacker could possibly use this issue to cause a
denial of service.
Source: USN-5821-3: pip regression