ref #777

DO NOT SEND ANY SECURITY FIX HERE. Please read "Security Reporting" section
on README.

What kind of change does this PR introduce? (check at least one)

• Bugfix
• Feature
• Code style update
• Refactor
• Other, please describe:

Does this PR introduce a breaking change? (check one)

• Yes
• No

If yes, please describe the impact and migration path for existing applications:

This affect the OAuth 2 framework clients authorize access token flow.

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