Hi,
Please read: Alkarex/EasyRSS#35 but actually I think this is an issue with FreshRSS itself.
In https://github.com/FreshRSS/FreshRSS/blob/master/p/api/greader.php#L520 you can see the response is served in plain JSON, so XML entity decoding of the <link> node content should have already happened, right?