Pale Moon version 28.11.0 has been released. The update is a development, bugfix and security update. Linux versions will follow shortly.
The update includes DiD ("Defense-in-Depth") updates. A DiD update is s a fix that does not apply to a (potentially) actively exploitable vulnerability in Pale Moon, but prevents future vulnerabilities caused by the same code, e.g. when surrounding code changes, exposing the problem, or when new attack vectors are discovered.
Update: To get the update now, select "Help" from the Pale Moon menu at the upper left of the browser window. Click About Pale Moon and Check for Updates.
Release Notes (http://www.palemoon.org/releasenotes.shtml)