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 the
TZ/tz items of DCH_to_char() with an error, instead of strcpy()ing
them past the palloc'd buffer (upstream 3d724bf4fd by Tom Lane,
carried on REL_14_STABLE inside 5fb3c63 and shipped in 14.24;
applies verbatim to 12.22).