- Mozilla Thunderbird 78.11.0
* OpenPGP could not be disabled for an account if a key was
previously configured
* Recipients were unable to decrypt some messages when the sender
had changed the message encryption from OpenPGP to S/MIME
* Contacts moved between CardDAV address books were not synced to
the new server
* CardDAV compatibility fixes for Google Contacts
MFSA 2021-26 (bsc#1186696)
* CVE-2021-29964 (bmo#1706501)
Out of bounds-read when parsing a `WM_COPYDATA` message
* CVE-2021-29967 (bmo#1602862, bmo#1703191, bmo#1703760,
bmo#1704722, bmo#1706041)
Memory safety bugs fixed in Thunderbird 78.11
- renewed expired mozilla.keyring

* CVE-2021-29956 (boo#1186199, bmo#1710290)
* CVE-2021-29957 (boo#1186198, bmo#1673241)