For more info, check out the release notes at the mozilla site.Security vulnerabilities fixed in Thunderbird 52.5
November 23, 2017
In general, these flaws cannot be exploited through email in the Thunderbird product because scripting is disabled when reading mail, but are potentially risks in browser or browser-like contexts.
#CVE-2017-7828: Use-after-free of PressShell while restyling layout
A use-after-free vulnerability can occur when flushing and resizing layout because the PressShell object has been freed while still in use. This results in a potentially exploitable crash during these operations.
#CVE-2017-7830: Cross-origin URL information leak through Resource Timing API
The Resource Timing API incorrectly revealed navigations in cross-origin iframes. This is a same-origin policy violation and could allow for data theft of URLs loaded by users.
#CVE-2017-7826: Memory safety bugs fixed in Firefox 57, Firefox ESR 52.5, and Thunderbird 52.5
Mozilla developers and community
Mozilla developers and community members Christian Holler, David Keeler, Jon Coppeard, Julien Cristau, Jan de Mooij, Jason Kratzer, Philipp, Nicholas Nethercote, Oriol Brufau, André Bargull, Bob Clary, Jet Villegas, Randell Jesup, Tyson Smith, Gary Kwong, and Ryan VanderMeulen reported memory safety bugs present in Firefox 56, Firefox ESR 52.4, and Thunderbird 52.4. Some of these bugs showed evidence of memory corruption and we presume that with enough effort that some of these could be exploited to run arbitrary code.