Via the Steam Store:

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:<br/> <ul style="padding-bottom: 0px; margin-bottom: 0px;" ><li>Updated the Roaring Rockets unusual taunt particle effect <li>Updated the equip_region for the Earbuds <li>Updated the models for the TFNew tournament medals to fix their broken LODs <li>Updated the localization files <li>Updated pl_fifthcurve_event<ul style="padding-bottom: 0px; margin-bottom: 0px;" ><li>Fixed a bug where players could spam "escaped from underworld"</ul>
<li>Updated koth_bagel_event<ul style="padding-bottom: 0px; margin-bottom: 0px;" ><li>Fixed a projectile bug that was occurring in RED's vent room <li>Updated some propfades on the lightbulbs in RED's valley</ul><li>Updated pl_rumble_event<ul style="padding-bottom: 0px; margin-bottom: 0px;" ><li>Fixed an exploit related to using the tiny spell and building sentries inside a wall <li>Bumper cars are now placed in a random order in underworld, after main world has run out of time or ended by explosion <li>Fixed bumper car race instructional text not showing to all players <li>Fixed Merasmus sometimes using his round-beginning lines in the middle of the round</ul><li>Updated koth_slasher<ul style="padding-bottom: 0px; margin-bottom: 0px;" ><li>Fixed the clipping issues in the spawn yards and in BLU's mineshaft <li>Fixed a case where the control point is unlocked while Merasmus is hiding</ul><li>Updated pd_monster_bash<ul style="padding-bottom: 0px; margin-bottom: 0px;" ><li>Fixed a gap in the spiral stairs that players could slip through when using the tiny spell <li>Fixed a kill trigger not always killing players in the dungeon <li>Fixed players taking fall damage when passing through the pit to the dungeon</ul><li>Updated pd_cursed_cove_event<ul style="padding-bottom: 0px; margin-bottom: 0px;" ><li>Fixed projectiles colliding with the waves at the shore <li>Fixed projectiles colliding with the capzone mist effect in locker <li>Fixed players sometimes getting stuck when exiting the locker <li>Adjusted particles on the pickups <li>Increased music volume <li>Added sound to the ship moving through the town (Thanks Spipper) <li>Added sound to the zone closing in the locker <li>Optimization tweaks <li>Various small detail fixes</ul></ul>