400 Bad Request error for issue links with % in slug (BB-2003)

I've created an issue in a private repository. It has Russian name and contain '%' sign.

Bitbucket returns "400 Bad Request" error if it is accessed using this link:
/issue/58/%2nffbpobicciho1agak5ahxh3bqcjnb7cxalzb0qy

By leaving just /issue/58/ I was able to view the issue.