[SNYK: Medium] Improper Input Validation (Due 04/15/2022)

[patphongs]

Overview
Pillow is a PIL (Python Imaging Library) fork.

Affected versions of this package are vulnerable to Improper Input Validation. When the path to the temporary directory on Linux or macOS contained a space, this would break removal of the temporary image file after im.show() (and related actions), and potentially remove an unrelated file.

Snyk vulnerability report:
https://security.snyk.io/vuln/SNYK-PYTHON-PILLOW-2397241
Closed Snyk-generated PR:
#5061

Tech considerations:
Ensure that our Wagtail version is compatible with the upgrade to 9.0.1

How to fix?
Upgrade Pillow to version 9.0.1 or higher.

Completion criteria

• Pillow is upgraded to version 9.0.1 or higher.