This is an "important fixes only" release in case you don't want to upgrade to v2.3.15. There is no matching Pigeonhole release - use the same v2.3.14 instead.
* CVE-2021-29157: Dovecot does not correctly escape kid and azp fields in
JWT tokens. This may be used to supply attacker controlled keys to
validate tokens, if attacker has local access.
* CVE-2021-33515: On-path attacker could have injected plaintext commands
before STARTTLS negotiation that would be executed after STARTTLS
finished with the client.
- lib-index: Corrupted mime.parts in dovecot.index.cache may have
resulted in Panic: file imap-bodystructure.c: line 206 (part_write_body):
assertion failed: (text == ((part->flags & MESSAGE_PART_FLAG_TEXT) != 0))
- imap: SETMETADATA could not be used to unset metadata values.
Instead NIL was handled as a "NIL" string. v2.3.14 regression.