Last Updated: March 30, 2026
This guide provides the official Samsung Galaxy S26 Ultra SM-S948U firmware, the correct Odin version, and clear instructions to unbrick, bypass FRP, or perform a clean reflash. If your device will not turn on or is stuck on the boot screen, follow these steps to restore it.
Device: Samsung Galaxy S26 Ultra SM-S948U | Chipset: Qualcomm Snapdragon 8 Elite Gen 5 for Galaxy (SM8850) | Flash Tool: Odin
Android: Android 16, One UI 8.5 | File Type: .tar.md5 / ZIP (Contains AP, BL, CP, CSC files for Odin)
⚠ Warning: Flashing erases all data. Back up first.
Device: Samsung Galaxy S26 Ultra SM-S948U (Qualcomm Snapdragon 8 Elite Gen 5 for Galaxy (SM8850))
Flash Tool: Odin
Latest Build: S948USQU1AZCF
Firmware Files: 1 available
What You Need: Windows PC, USB data cable, Odin, USB drivers
Time Required: 10-20 minutes (plus 3-8 min first boot)
Samsung Galaxy S26 Ultra SM-S948U Firmware (Flash File) Drivers, Tools & Guide
Flashing Samsung firmware with Odin is straightforward once you know what to look out for. This page contains everything you need: the correct firmware file for the Samsung Galaxy S26 Ultra SM-S948U, the proper Odin version, and the steps that work.
One important step before you start: if your device has a Samsung account signed in, sign it out before doing anything else. Knox will trigger if this step is skipped, and dealing with a KG lock after flashing takes extra time. Also, Samsung firmware comes in .tar.md5 format, after extracting the ZIP, you should see files named AP_*, BL_*, CP_*, and CSC_* (or HOME_CSC_*). If you do not see these, you have the wrong package.
The Samsung Galaxy S26 Ultra SM-S948U is a relatively recent device (released 2026), so you should expect active firmware updates and good driver support on modern Windows systems. Only one firmware build is currently available for the Samsung Galaxy S26 Ultra SM-S948U. This is the stock ROM you should use for recovery, unbricking, or FRP bypass. Powered by a Qualcomm Snapdragon 8 Elite Gen 5 for Galaxy (SM8850) (Qualcomm) processor, the Samsung Galaxy S26 Ultra SM-S948U requires Qualcomm Flash Image Loader (QFIL) and Qualcomm HS-USB drivers. Make sure to install the correct driver package before connecting your device.
This firmware was sourced directly from verified repositories and checked for integrity before being listed on this page. Samsung firmware uses a multi-file system (AP, BL, CP, CSC) specific to Odin-based flashing, which differs from single-file scatter-based tools.
Your Samsung Galaxy S26 Ultra SM-S948U firmware comes as a compressed ZIP file. Download and extract it using WinRAR or 7-Zip. After extracting, you should see files named like AP_*.tar.md5, BL_*.tar.md5, CP_*.tar.md5, and CSC_*.tar.md5 (or HOME_CSC_*.tar.md5). If you do not see these files, you may have the wrong firmware package for your device.
This process restores the phone to its original factory state, which means all your personal data will be lost. That clean wipe is exactly what fixes persistent problems like bootloops, forgotten locks, Google account verification, battery drain, and system errors.
FRP Removal for Samsung Galaxy S26 Ultra SM-S948U
The fastest way to bypass FRP on Samsung Galaxy S26 Ultra SM-S948U is to use a free Android apps launcher that lets you access settings during the setup wizard. After flashing or performing a factory reset you may see a Google account lock (FRP). Our free Android apps launcher is the fastest way to get past it. This is also why I always recommend removing your Google account before flashing, it avoids this problem entirely.
How to Wipe Samsung Galaxy S26 Ultra SM-S948U to Factory Settings
To factory reset Samsung Galaxy S26 Ultra SM-S948U without a computer, power off the device completely, then hold Volume Up + Power (for older models with a Home button, use Volume Up + Home + Power) at the same time until the recovery menu appears. Use the volume keys to navigate to “Wipe Data/Factory Reset” and confirm with the Power button.
A hard reset erases all data and restores Samsung Galaxy S26 Ultra SM-S948U to its original factory state. This fixes most software problems, slow performance, app crashes, forgotten screen locks, and bootloops. If the issue persists after a factory reset, a full firmware flash using Odin is covered in the following sections.
Samsung Galaxy S26 Ultra SM-S948U Firmware Compatibility Check
The single biggest mistake I see people make is flashing firmware meant for a different variant. Before downloading anything, verify your exact device identity:
- Identify Your Exact Model Number: Go to Settings › About Phone and note your full model number (e.g. SM-S948U). The letter suffix matters, U/U1 = USA, W = Canada, N = Korea, B/F = International/Global. Flashing firmware built for a different variant can cause issues.
- Match the CSC (Region): The 3-letter region code in the firmware filename must match your device. Check Settings › About Phone › Software Information for your current CSC, or look at the Service Provider line in Download Mode. Common codes: XAA (US), BTU (UK), INS (India), SER (Russia).
- Check the Binary Level: Look at the version string in your current firmware (e.g.
XXU9BZDP, the number after the letters is the binary level). You cannot downgrade to a lower binary level. If your device is on Binary 9, only flash Binary 9 or higher firmware. - Confirm the Build Date: The last 4 characters of the PDA version encode the build date, first character is the year (A=2024, B=2025, C=2026), second is the month (A=Jan through L=Dec).
- Verify in Download Mode: Power off, hold Volume Down + Power to enter Download Mode. This screen shows your exact model, CSC, and current firmware version, use this to confirm before flashing.
When Should You Flash Samsung Galaxy S26 Ultra SM-S948U?
Samsung devices like the Samsung Galaxy S26 Ultra SM-S948U are flashed using Odin, regardless of the chipset inside. Whether you are dealing with a boot issue or a software problem, flashing the official firmware can resolve it:
- Clear a forgotten screen lock, PIN, or pattern without needing the original credentials.
- Restore system apps that were accidentally removed or corrupted.
- Remove persistent malware or adware that survives a factory reset.
- Fix startup loops, lagging, and freezing on your device.
- Repair a phone that shuts down randomly or restarts in a loop.
- Resolve OTA update failures and battery drain issues.
- Recover from KG lock or Knox-related issues after an incorrect or interrupted flash on your device.
Learn more about stock ROMs and why flashing works.
Firmware Details for Samsung Galaxy S26 Ultra SM-S948U
Here is a quick overview of the official firmware specifications:
| Firmware Information | Details |
|---|---|
| Device Model | Samsung Galaxy S26 Ultra SM-S948U |
| Firmware Version | S948USQU1AZCF |
| File Size | 18 GB |
| Android Version | Android 16, One UI 8.5 |
| Platform | Qualcomm Snapdragon 8 Elite Gen 5 for Galaxy (SM8850) |
| Release Date | Released 2026, March 06 |
| Region | SM |
| File Type | .tar.md5 / ZIP (Contains AP, BL, CP, CSC files for Odin) |
Which Firmware Version Should I Download?
This is the question I get asked most often in the comments, so I put together a simple guide. Find your situation in the table and go straight to the right file:
| Your Situation | What I Recommend |
|---|---|
| Phone is completely dead or stuck on logo | S948USQU1AZCF, download this one. It is the latest Samsung Galaxy S26 Ultra SM-S948U firmware available. |
| FRP / Google account lock only | See the FRP bypass guide above, you likely do not need the full firmware for this. |
| Not sure which region/CSC to download | Check Settings › About Phone › Software Information for your current CSC, or enter Download Mode (Volume Down + Power), it shows the CSC on screen. Match the 3-letter code (e.g. XAA, BTU, INS) to the firmware filename. |
| Phone slow after a recent OTA update | Try the next older version, sometimes the latest OTA introduces new bugs and an older build runs better. Make sure the binary level is the same or higher than what your device currently has. |
| IMEI missing after a previous flash | Re-flash S948USQU1AZCF first, then follow the IMEI repair guide. Do not skip the reflash. |
| S948USQU1AZCF failed with a flash error | Try the next older version instead and double-check your AP/BL/CP/CSC file assignments in Odin before assuming the firmware is the problem. |
| Restoring to factory / warranty repair | S948USQU1AZCF, clean state, fresh start. |
To tell which Samsung firmware is newer, look at the last 4 characters of the PDA version string (e.g. S938BXXU9CZDP). The first character is the year (A=2024, B=2025, C=2026), the second is the month (A=Jan, B=Feb… L=Dec, Z=final stable), and the last two are the revision (0-9 then A-Z, where Z is highest). But before comparing dates, always check the binary level: the digit just before the date code (e.g. XXU9CZDP = Binary 9). You cannot downgrade to a lower binary level. If your device is on Binary 9, only flash Binary 9 or higher. Also make sure the 3-letter CSC code in the firmware matches your device region.
Download Samsung Galaxy S26 Ultra SM-S948U Firmware
Download the official stock firmware for your Samsung Galaxy S26 Ultra SM-S948U below. The latest available version is S948USQU1AZCF. After downloading, verify the file size matches the table above, a size mismatch usually means a partial or corrupt download, and flashing a corrupt file can cause more problems than it solves.
| Software Details | Download Link | Members Link |
|---|---|---|
|
File Name: SM-S948U_S948USQU1AZCF_S948UOYN1AZCF_ATT_5file.zip Size: 18 GB | Download Link | Download Link2 |
Only download firmware that is fully compatible with your exact device model. See the firmware selection guide above if you are not sure.
Important: The Samsung Galaxy S26 Ultra SM-S948U (SM-S948U) should not be confused with other Galaxy S26 Ultra variants that may have different chipsets or regional firmware. Even devices in the same Galaxy S26 Ultra line can use completely different processors. Always verify your exact model code “SM-S948U” in Settings > About Phone before downloading any firmware from this page.
- Your model number is a variant of SM-S948U with a different letter suffix. Check About Phone carefully, one letter difference can cause a failed or broken flash.
- Your chipset differs from Qualcomm Snapdragon 8 Elite Gen 5 for Galaxy (SM8850). Confirm in recovery mode before proceeding.
- You downloaded the file from a source other than this page.
- The file size differs significantly from the sizes listed in the table above, a size mismatch usually means a partial download, which will fail mid-flash.
What You Need Before Flashing Samsung Galaxy S26 Ultra SM-S948U
Go through this list before you open Odin for the Samsung Galaxy S26 Ultra SM-S948U. Two things that commonly cause problems with Samsung devices: a Samsung account that was not signed out before flashing, which can trigger KG lock, and a USB cable that works for charging but drops the connection mid-flash. Always use a proper data cable, not a charge-only cable.
- Back Up IMEI Numbers: Dial *#06# and write down both IMEI numbers now. You will need these if you need to restore your IMEI after flashing.
- Remove Google Accounts: Sign out of all Google accounts to prevent FRP lock after flashing.
- Remove Samsung Accounts: Sign out of all Samsung accounts to avoid KG lock.
- Back Up Your Data: Back up everything, photos, contacts, WhatsApp chats, important files. Flashing wipes the device completely.
- Charge Your Device: At least 50% battery. A device that powers off during a flash is very difficult to recover.
- USB Cable & PC: Use a proper data USB cable, not a charge-only cable, and a Windows computer with available USB ports.
- Install Required Drivers:
Step-by-Step: Flash Samsung Galaxy S26 Ultra SM-S948U Stock ROM
We are using Odin for this. A quick tip: keep “Auto Reboot” and “F. Reset Time” both checked in Odin, those two options together give you the cleanest flash result. If you are not sure which Odin version to use, check our Odin versions page. Some older Samsung devices work better with older Odin builds.
- Prepare the Flash Files:
- Go to the download section and grab the firmware package that matches your device.
- Unzip the file to a folder on your desktop. Avoid using folder names with non-English characters or spaces, the flash tool may not read them correctly.
- Confirm Driver Setup:
- The drivers listed in prerequisites need to be installed and working before you connect the phone. If you are not sure, reinstall them and restart your computer.
- Load the Firmware File:
- In Odin, click “BL” and select the BL_*.tar.md5 file. Click “AP” and select the AP_*.tar.md5 file. Repeat for “CP” and “CSC”. Use HOME_CSC to keep data, or CSC for a clean flash.
- Connect Your Device:
- Enter Download Mode: Turn off your phone, then hold Volume Down + Power (add Home button on older models) until the warning screen appears. Press Volume Up to confirm and enter Download Mode.
- Connect your phone to your PC via USB. Odin should show “Added..” in the log area, this means your device is detected.
- Start Flashing:
- Click “Start” to kick off the firmware write.
- Hands off the phone and cable until the tool shows completion. Moving or disconnecting the device mid-flash is the most common cause of a bricked phone.
- Wait and Reboot:
- When you see the success message, disconnect the USB cable.
- Hold the power button to boot the phone. Give it a solid 5 to 8 minutes for the first startup, this is normal.
Video Guide for Flashing
Troubleshooting Samsung Galaxy S26 Ultra SM-S948U Flash Errors
- Odin Shows “FAIL” Instead of “PASS”:
- This is usually a mismatch between the firmware region or model and your device. Confirm your exact model number in Settings › About Phone before selecting the firmware. Even a single letter difference in the model code matters.
- Samsung Galaxy S26 Ultra SM-S948U Not Recognized by Odin:
- Reinstall the Samsung USB drivers. Make sure you are in Download Mode. Try a different USB cable, Odin can be sensitive to cable quality.
- KG Lock / Knox Triggered After Flashing:
- This happens when a Samsung account was still signed in before flashing, or when unofficial firmware was used. Always sign out of Samsung accounts before flashing. If KG lock is already active, a professional unlocking tool is generally needed.
- Boot Loop After Flashing:
- Enter recovery mode (Volume Up + Power) and perform a factory reset. This clears any leftover data from the previous firmware that may be causing the conflict.
Normal Behavior After Installing Samsung Galaxy S26 Ultra SM-S948U Firmware
Here is what is completely normal after a successful flash:
- How to know the flash was successful: Odin will show “PASS.” in green text at the top-left of the log area. If you see this, everything went fine.
- First boot takes 3 to 8 minutes, do not force-reboot the device. The operating system is setting itself up from scratch. Interrupting this is how devices end up in bootloops.
- Notification sounds and ringtones will be back to factory defaults. Any custom tones you had set before will need to be re-downloaded and re-assigned in Settings.
- The phone may ask for language and region again, this is normal after a flash. You are starting from a clean state, so the setup wizard runs just like when the phone was brand new.
- Stuck in a bootloop after first boot? Enter recovery mode and do a factory reset from there, see the hard reset guide above. This can happen occasionally and does not mean the firmware is wrong.
- The phone will feel warm during first boot, this is normal. It settles after a few minutes once the initial app setup is complete.
- Be careful when re-adding your Google account, if you did not remove it before flashing, you may see an FRP prompt. Add it fresh during the setup wizard, not afterwards through Settings.
Missing IMEI or Corrupt Baseband on Samsung Galaxy S26 Ultra SM-S948U After Flashing?
A missing IMEI on a Samsung device after flashing usually points to a corrupted EFS partition, this is the partition that stores your IMEI and carrier settings. Note that restoring an IMEI that is not your original number is illegal in most countries, so only do this if you are restoring the number the device had before you flashed. Tools like ChimeraTool or BFT can help with this. Check your local laws before proceeding.
Video Guide: How to repair IMEI
Frequently Asked Questions
Q1: My device is not detected by Odin. What should I do?
A: Start with the drivers, reinstall the Samsung USB drivers, restart your PC, then try again. Switch to a USB 2.0 port if you are on USB 3.0. Disable your antivirus temporarily. If none of that works, leave a comment with the exact error message.
Q2: What should I do if I encounter an FRP lock after flashing?
A: Use our free Android apps launcher. FRP lock activates when a Google account was still signed in before flashing. This is why signing out of your Google account before flashing avoids this issue entirely.
Q3: Is it safe to flash during a power outage risk?
A: It is best to avoid flashing during unstable power conditions. If your PC shuts down during the flash, it can corrupt the write and leave the phone in an unbootable state. If you are in an area with unreliable power, use a laptop with a fully charged battery instead of a desktop.
Q4: Will flashing erase my data?
A: Yes, flashing with Odin restores the device to factory state, including Android 16, One UI 8.5 default settings. All apps, photos, contacts, and accounts will be removed. Back up everything you need before you start. There is no way to recover data once the flash is complete.
Q5: Will flashing void my warranty?
A: Flashing official stock firmware generally does not void your warranty since you are restoring the device to its factory-intended state. However, some manufacturers may flag that the bootloader was unlocked or that the flash counter increased. Check your specific warranty terms with Samsung support if you are concerned.
Q6: My IMEI shows “unknown” after flashing. Is my phone permanently damaged?
A: No, it looks alarming, but it is fixable. Follow the IMEI repair guide in the troubleshooting section above. For Samsung devices, check for EFS partition corruption first. Do not insert a SIM card until the IMEI is restored.
Q7: What if the flash fails halfway through?
A: Do not panic and do not disconnect the phone. Close Odin, restart it, and try the flash again from the beginning. In most cases, a failed flash just means the process needs to be repeated. The device is usually still detectable by the flash tool even after a failed attempt.
Q8: Can I use a Mac or Linux computer for this?
A: Samsung firmware can be flashed using Heimdall on Linux or Mac, but the instructions on this page are written for Odin on Windows. If you only have a Mac, you may want to use a Windows virtual machine or Boot Camp for the most straightforward experience.
People Also Ask About Samsung Galaxy S26 Ultra SM-S948U
What is the latest firmware version for Samsung Galaxy S26 Ultra SM-S948U?
The latest available Samsung Galaxy S26 Ultra SM-S948U firmware on this page is version S948USQU1AZCF. This page has 1 firmware build available for download. Check the firmware details table above for file sizes and Android versions.
How do I check my Samsung Galaxy S26 Ultra SM-S948U model number before flashing?
Go to Settings > About Phone on your Samsung Galaxy S26 Ultra SM-S948U and look for the model number “SM-S948U”. You can also confirm by entering recovery mode (Volume Up + Power while powered off) which displays the build number and model code. Always match this exactly with the firmware filename before flashing.
What chipset does the Samsung Galaxy S26 Ultra SM-S948U use?
The Samsung Galaxy S26 Ultra SM-S948U is powered by the Qualcomm Snapdragon 8 Elite Gen 5 for Galaxy (SM8850), a Qualcomm processor. Flashing requires QFIL (Qualcomm Flash Image Loader) and Qualcomm HS-USB QDLoader drivers. The device must be in EDL (Emergency Download) mode for firmware installation.
Will flashing firmware on Samsung Galaxy S26 Ultra SM-S948U erase my data?
Yes. Flashing stock firmware on the Samsung Galaxy S26 Ultra SM-S948U with Odin performs a full factory reset. All apps, photos, contacts, and accounts will be removed. Back up everything important before you start. There is no way to recover data after flashing.
Wrapping Up: Samsung Galaxy S26 Ultra SM-S948U Firmware
Your Samsung Galaxy S26 Ultra SM-S948U should now be running S948USQU1AZCF on a clean build. If the first boot takes a while, do not worry, that is completely normal after a fresh flash.
Ran into something unexpected? Leave a comment and describe what happened. Include which step you were on and what error you saw. I will get back to you.
Consider sharing this guide with anyone else who has a Samsung device that needs fixing.
Browse all Samsung firmware downloads for more devices.
Disclaimer: Flashing stock firmware is performed at your own risk. Follow the instructions on this page carefully. I cannot be held responsible for any damage to your device, but I will always try to help if something goes wrong.
