WebKitGTK and WPE WebKit prior to version 2.24.1 failed to properly apply configured HTTP proxy settings when downloading livestream video (HLS, DASH, or Smooth Streaming), an error resulting in deanonymization. This issue was corrected by changing the way livestreams are downloaded.
https://usn.ubuntu.com/3948-1/
https://trac.webkit.org/changeset/243197/webkit
https://security.gentoo.org/glsa/201909-05
https://seclists.org/bugtraq/2019/Apr/21
https://bugs.webkit.org/show_bug.cgi?id=193718
http://www.openwall.com/lists/oss-security/2019/04/11/1
http://packetstormsecurity.com/files/152485/WebKitGTK-WPE-WebKit-URI-Spoofing-Code-Execution.html
http://lists.opensuse.org/opensuse-security-announce/2019-05/msg00031.html
http://lists.opensuse.org/opensuse-security-announce/2019-05/msg00025.html