Document changes and release 1:78.13.0-1

debian/changelog

+thunderbird (1:78.13.0-1) unstable; urgency=medium
+
+  * [b4498b0] New upstream version 78.13.0
+    Fixed CVE issues in upstream version 78.12 (MFSA 2021-35):
+    CVE-2021-29986: Race condition when resolving DNS names could have led to
+                    memory corruption
+    CVE-2021-29988: Memory corruption as a result of incorrect style treatment
+    CVE-2021-29984: Incorrect instruction reordering during JIT optimization
+    CVE-2021-29980: Uninitialized memory in a canvas object could have led to
+                    memory corruption
+    CVE-2021-29985: Use-after-free media channels
+    CVE-2021-29989: Memory safety bugs fixed in Thunderbird 78.13
+
+ -- Carsten Schoenert <c.schoenert@t-online.de>  Thu, 12 Aug 2021 16:13:25 +0200
+
 thunderbird (1:78.12.0-1) unstable; urgency=medium
 
   * [74d3cdb] New upstream version 78.12.0