This is a maintenance release to fix security reports since 4.4.9.
- Block binary/octal/hex/decimal based hostnames from being submitted in forms that could trigger an SSRF.
- Gfycat OEmbed endpoint could create XSS. Also informed Gfycat of issue. - Thanks to René Kroka - https://renekroka.cz for reporting this issue.
- Addition attachment permission checks when downloading attachments.