An update to Team Fortress 2 has been released. The update will be applied automatically when you restart Team Fortress 2. The major changes include:

Fixed an issue where plugin_load may load a non-binary file type
Fixed an issue where decompressed file sizes were not being checked by the engine
Fixed a client crash related to Unusual items and the character loadout screen
Fixed an item exploit where tools were being used for purposes other than the original intent
Fixed The Shortstop not using its crit sound when firing crits
Fixed the HUD achievement tracker not filtering map-specific achievements
Fixed an issue where character voice lines would be clipped
Fixed disguised Spies losing their disguised cosmetic items when they touch a supply closet
Fixed the HUD 3D Character equipping the wrong item when Spies change their disguised weapon
Fixed the Demoman's shield charge turn rate when using joystick input
Joystick input now matches keyboard/mouse input
Added new promo items
Added ETF2L 6v6 Season 17 and ETF2L Highlander Season 5 medals
Updated the localization files
Updated metal hats to sound like metal when they fall off players' heads
Updated the equip_regions for The Toss-Proof Towel, The Titanium Towel, The Tartan Shade, Marshall's Mutton Chops, Stockbroker's Scarf, The Carl, and The Polar Pullover
Updated cp_dustbowl
Fixed players standing in sky over the beginning of stage 1
Fixed collision on rocks in the front of stage 1 where stickybombs could be placed inside them
Updated cp_junction_final
Players are now prevented from building in spawn rooms
Updated ctf_2fort
Fixed players standing on conduits in flag rooms
Fixed players standing in sky over Red battlements
Fixed a missing face under the stairs in the Blu base ramp room that let players see enemies above
Fixed collision on props under stairs in Red's courtyard
Updated ctf_turbine
Fixed collision on spawn doors
Added prop to facilitate players jumping up to raised platform and fixed surrounding collision
Fixed collision under stairs in mid room
Fixed misc prop collision
Fixed collision on signs in mid room
Fixed the clipping in the rafters of flag rooms
Increased performance with addition of area portals
Added decals under ammo and health packs
Smoothed geometry in the vents
Added nobuild around spawn doors
Added light props over Red and Blu gate 1 doorways
Updated koth_lakeside_event
Updated koth_lakeside_final
Fixed bot navigation errors
Prevented players from building in spawn room doors
Fixed rock piles to mirror on Red and Blu sides
Updated pl_goldrush
Fixed players shooting projectiles through the window in the mining tower into Red's first spawn and Blu's second spawn
Fixed players standing in sky above Blu spawn in stage 3
Fixed player clipping exploit above the Blu exit in stage 3