Core:
    Preloading support on Windows has been disabled.
    Fixed bug #79022 (class_exists returns True for classes that are not ready to be used).
    Fixed bug #78929 (plus signs in cookie values are converted to spaces).
    Fixed bug #78973 (Destructor during CV freeing causes segfault if opline never saved).
    Fixed bug #78776 (Abstract method implementation from trait does not check "static").
    Fixed bug #78999 (Cycle leak when using function result as temporary).
    Fixed bug #79008 (General performance regression with PHP 7.4 on Windows).
    Fixed bug #79002 (Serializing uninitialized typed properties with __sleep makes unserialize throw).
CURL:
    Fixed bug #79033 (Curl timeout error with specific url and post).
    Fixed bug #79063 (curl openssl does not respect PKG_CONFIG_PATH).
Date:
    Fixed bug #79015 (undefined-behavior in php_date.c).
DBA:
    Fixed bug #78808 ([LMDB] MDB_MAP_FULL: Environment mapsize limit reached).
Exif:
    Fixed bug #79046 (NaN to int cast undefined behavior in exif).
Fileinfo:
    Fixed bug #74170 (locale information change after mime_content_type).
GD:
    Fixed bug #79067 (gdTransformAffineCopy() may use unitialized values).
    Fixed bug #79068 (gdTransformAffineCopy() changes interpolation method).
Libxml:
    Fixed bug #79029 (Use After Free's in XMLReader / XMLWriter).
Mbstring:
    Fixed bug #79037 (global buffer-overflow in `mbfl_filt_conv_big5_wchar`). (CVE-2020-7060)
OPcache:
    Fixed bug #78961 (erroneous optimization of re-assigned $GLOBALS).
    Fixed bug #78950 (Preloading trait method with static variables).
    Fixed bug #78903 (Conflict in RTD key for closures results in crash).
    Fixed bug #78986 (Opcache segfaults when inheriting ctor from immutable into mutable class).
    Fixed bug #79040 (Warning Opcode handlers are unusable due to ASLR).
    Fixed bug #79055 (Typed property become unknown with OPcache file cache).
Pcntl:
    Fixed bug #78402 (Converting null to string in error message is bad DX).
PDO_PgSQL:
    Fixed bug #78983 (pdo_pgsql config.w32 cannot find libpq-fe.h).
    Fixed bug #78980 (pgsqlGetNotify() overlooks dead connection).
    Fixed bug #78982 (pdo_pgsql returns dead persistent connection).
Session:
    Fixed bug #79091 (heap use-after-free in session_create_id()).
    Fixed bug #79031 (Session unserialization problem).
Shmop:
    Fixed bug #78538 (shmop memory leak).
Sqlite3:
    Fixed bug #79056 (sqlite does not respect PKG_CONFIG_PATH during compilation).
Spl:
    Fixed bug #78976 (SplFileObject::fputcsv returns -1 on failure).
Standard:
    Fixed bug #79099 (OOB read in php_strip_tags_ex). (CVE-2020-7059)
    Fixed bug #79000 (Non-blocking socket stream reports EAGAIN as error).
    Fixed bug #54298 (Using empty additional_headers adding extraneous CRLF).