SM-L3550 1 country Wear OS 7.0

Samsung Watch9 44mm L3550ZCS1AZH4 Firmware

Samsung Watch9 44mm L3550ZCS1AZH4 is an Wear OS 7.0 firmware for China (CHC). It is the same firmware configured per region and carrier (CSC). Find your country below, verify the file and download for free. Compared with the previous build L3550ZCU1AZG1: security patch 2026-08-05 instead of 2026-05-05. This is the newest build for SM-L3550.

Download firmware
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Wear OS 7.0
OS Version
2026-08-31
Build Date
2026-08-05
Security patch
1
Countries
1
CSC codes
1
Bootloader binary

Bootloader binary 1. Flashing firmware with a lower binary is usually blocked by Samsung anti-rollback.

All regional downloads

Pick your region (CSC) to download the matching firmware package.

Paste your current build number from Settings > About phone (About tablet) > Software information, or the output of *#1234#.
    MODEM/CP Version: L3550ZCS1AZH4
    ModelRegionCSC VersionRelease dateSizeFile nameDownload
    SM-L3550
    CHC China
    		L3550CHC1AZH4 2026-08-31 3.259 GiB
    SM-L3550_1_20260831100741_z2zj3b2zji_fac.zip
    		Download

    No matching downloads

    How to flash L3550ZCS1AZH4

    • L3550ZCS1AZH4 has bootloader binary 1. Your device must run binary 1 or lower: it is the 5th character from the end of your current build number.
    • CSC: Use CSC for a clean install, to change the region (CSC code), to downgrade or to repair a device that does not boot.
    • HOME_CSC: Use HOME_CSC to update the same model and region while keeping your data. Back up anyway: a failed update can still require a reset.
    • The Download Mode key combo depends on the model: see all combos.
    Full flashing guide
    Beware: Manually flashing firmwares may brick your device. Use it at your own risk and follow our tutorial steps.

    What's new in L3550ZCS1AZH4

    • Security
    The device is protected with improved security.

    These changes may vary depending on the model, country, or network operator of the customer environment.

    Security patch: August 2026

    SMR Aug-2026 fixes 54 vulnerabilities, 8 of them critical. Android Security Bulletin: 38, Samsung-specific issues (SVE): 16.

    Most severe Samsung fixes:

    • high Improper access control in Weaver prior to SMR Aug-2026 Release 1 allows local attackers to cause device inoperability. (CVE-2026-21064)
    • high Improper input validation in Galaxy Themes prior to SMR Aug-2026 Release 1 allows physical attackers to launch arbitrary activity. (CVE-2026-21073)

    All fixes and Galaxy models with this patch

    Device specifications

    • Launched withWear OS
    • Display diagonal3.81 cm (1.5")
    • Display technologyAMOLED
    • Display resolution480 x 480 pixels
    • RAM2 MB
    • Battery capacity445 mAh
    • Weight34 g
    • Band colourGreen

    Specifications of SM-L355F, a regional variant of the same device. Chipset and SIM lines are left out: they can differ by region.

    Frequently Asked Questions

    L3550ZCS1AZH4 is Wear OS 7.0 firmware for Samsung Watch9 44mm, released for China (CHC). It includes the 2026-08-05 security patch. Samsung built it on 2026-08-31.

    SMR Aug-2026 fixes 54 vulnerabilities, 8 of them critical. Android Security Bulletin: 38, Samsung-specific issues (SVE): 16.

    Yes. L3550ZCS1AZH4 is the newest build for SM-L3550 on SamFirm. The previous build was L3550ZCU1AZG1.

    Download the package for your region (CSC) and unzip it. In Odin, load each file into the slot with the same name: BL, AP, CP (if the package has one) and CSC, or HOME_CSC to keep your data. Odin checks the built-in checksum of every .tar.md5 file before flashing. The download is 3.259 GiB; keep about twice that free on the computer to unzip it. The Samsung Watch9 44mm must be on bootloader binary 1 or lower.

    This build uses bootloader binary 1. It can be flashed on a Samsung Watch9 44mm running binary 1 or lower; if the device already has a higher binary, Odin stops with "SW REV CHECK FAIL". 1 other build of this model uses the same binary, so you can switch between them in both directions.

    Other builds and changelog for Samsung Watch9 44mm

    • Security
    The device is protected with improved security.

    These changes may vary depending on the model, country, or network operator of the customer environment.

    · Device stability improvements, bug fixes.
    · New and / or enhanced features.
    · Further improvements to performance.

    Model firmware by region