Announced in February 2014, Samsung Galaxy S5 is now available for purchase in several countries around the world. The Galaxy S5 comes in some variants and runs Android 4.4.2 KitKat out of the box.
Samsung Galaxy S5 users who wish to root their devices, may follow the tutorial below.
This tutorial uses CF-Auto-Root file released by Senior Recognized XDA-Developers, Chainfire. Head over to the CF-Auto-Root main thread to learn more about the root method.
Disclaimer: Rooting voids the warranty of your device. We and the developer of this rooting procedures shall not be held responsible if any undesirable outcomes may happen to your device. use of this root guide is solely at your own risk!

Pre-requisites
1. Install USB Drivers for Samsung Galaxy S5 on the computer.
2. Enable USB Debugging Mode on the phone by navigating to Settings >> Developer Options.
3. Make a backup of all your important data before following the guide.
4. Ensure the battery of the phone is charged more than 80 percent.
5. The CF-Auto-Root file works only on the Galaxy S5. Applying this to any incorrect variant might brick the device. Verify the model number of the Galaxy S5 by navigating to Settings >> About Phone.

Files Required
1. CF-Auto-Root

• SM-G900F (International Qualcomm)
• SM-G900H (International Exynos)
• SM-G900M (Middle and South America)
• SM-G900R4 (US Cellular)
• SM-G900T (T-Mobile US)
• SM-G900P (Sprint)
• SM-G900T1 (Metro PCS)
• SM-G900W8 (Canada)

2. Odin 3.09

Steps to Root Galaxy S5 Running on Android 4.4.2 KitKat Firmware
Step 1: Extract CF-Auto-Root and Odin 3.09 files using WinRAR/7-Zip/WinZip or any other extracting tool.
Step 2: Switch off the Galaxy S5. Then boot into Download Mode by pressing and holding Volume Down, Home and Power buttons together until a construction Android robot icon with a warning triangle appears on screen. Now press the Volume Up button to enter Download Mode.
Step 3: Launch Odin on the computer as an Administrator.
Step 4: Connect the Galaxy S5 to the computer using USB cable while it is in the Download Mode. Wait until Odin detects the device. When the device is connected successfully, the ID: COM box will turn to light blue with the COM port number. Additionally, the successful connected will be indicated by a message saying Added.
Step 5: In Odin, click the AP button and select the CF-Auto-Root .tar.md5 file.
Step 6: Verify that Auto Reboot and F. Reset Time checkboxes are selected in Odin. Also, ensure the Re-Partition option is NOT selected.
Step 7: Double-check and click Start in Odin. The installation process will now begin.
Step 8: Once the installation process completes, your phone will restart and soon you will see a PASS message with green background in the left-most box at the very top of the Odin. You can now unplug the USB cable to disconnect it from the computer.

Samsung Galaxy S5 running on Android 4.4.2 KitKat is now rooted successfully. You can now install any app that requires root permission. Verify the root status of the device by downloading Root Checker app from Google Play Store.

Note: Many Samsung devices store a flash counter that keeps track of how many times you have flashed custom firmwares to your device. Triangle Away can be used to reset the flash counter to zero.

Thank's to all fellas at XDA who first tried out this rooting technique. This method was originally posted via XDA-Developers original thread.