SECURITY UPDATE: Heap buffer overflow in to_char(timestamptz):
DCH_to_char() copies the timezone abbreviation into a
DCH_MAX_ITEM_SIZ-budgeted workspace with an unchecked strcpy(), and
any client can select a longer POSIX abbreviation via SET TIME ZONE
(CVSS 8.8, arbitrary code execution as the database OS user).
debian/patches/CVE-2026-14669.patch: reject POSIX timezone
abbreviations longer than n->key->len * DCH_MAX_ITEM_SIZ in
DCH_to_char()'s TZ/tz items with an error instead of strcpy()ing
them past the palloc'd buffer (upstream 12a6206864, folded into
REL_14_STABLE 5fb3c638 and shipped in 14.24; applies verbatim).