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:
General:

• Fixed Quick-Fix infinite heal exploit
• Fixed missing Cow Mangler 5000 particles when running in DirectX8
• Fixed Disco Beat Down unusual effect showing through walls
• Fixed incorrect projectile speed attributes being applied to giants in Mann vs. Machine
• When disguised as a teammate, the Dead Ringer will drop the body of the player the Spy is disguised as
• Fixed a bug where arrows and bolts would hit friendly players
• Fixed a bug where Strange parts and filters could not be removed from Strange weapons
• Fixed the "Show Entire Backpack" option in the crafting panel not preserving empty backpack slots and forcing items to stack

Maps:

• Fixed an areaportal improperly rendering in pl_goldrush
• Fixed players getting out of map in cp_standin
• Fixed players hiding in vents in cp_standin
• Adjusted HDR lighting in cp_process