Support for Nintendo Switch 23.5.0
Atmosphère 1.12.2 is the project’s ninety-fifth official release, published on November 11, 2026. Its main change is basic support for Nintendo Switch system software 23.5.0, alongside general system stability improvements.
The release also includes the broader 1.12-series work for system software 23.0.0. That work updates Atmosphère’s handling of the secure monitor, kernel, boot process and several system services so the customized firmware can continue to boot and operate with the newer Nintendo software environment. The project describes the 23.0.0 support as allowing the console to boot with Atmosphère fully functional.
Update fusee with the new release
Users upgrading to Atmosphère 1.12.2 must update fusee at the same time. The release notes specifically state that fusee-primary no longer exists and will not work with this version, so an older fusee-primary setup should not be retained when upgrading.
The supplied package includes a fusee.bin file alongside the main Atmosphère archive. The release notes do not provide additional installation steps, so the important documented requirement is to use the updated fusee component rather than fusee-primary.
More memory for custom system modules
Nintendo’s changes in system software 23.0.0 reduced the memory that could be taken from the applet pool. Without further changes, that would have made it impossible to launch browser applets such as the eShop without crashing while still providing room for custom system modules.
Atmosphère 1.12 introduced patches for the systemWeb, openWeb and LibAppletOff browser applets. These patches remove allocations from memory that the applets mark as reserved but do not access, allowing Atmosphère to reclaim roughly 9 MB. The project says this experimentally raises the memory available to custom system modules to 16 MB.
The release notes describe preliminary testing as showing no apparent downside for the operating system or browser applets, while also asking users to report problems that could reveal edge cases. The patches may be replaced or removed in a future version if a better approach is developed.
Kernel, secure monitor and system component updates
The exosphere component was updated to match the latest official secure monitor behavior. This includes support for a new ConfigItem, the first such addition to the secure monitor since Nintendo Switch system software 5.0.0.
Mesosphere now reflects further kernel changes. The kernel supports a 42-bit address space, introduces a memory region called ShadowStack and uses CTR-DRBG for kernel random-number generation. These are low-level compatibility changes that help Atmosphère track the behavior expected by newer system software.
The boot component was updated to match an official change to battery I2C shutdown behavior that arrived in system software 18.0.0. The release notes say this change may be connected to a battery-draining issue reported from around that version, although further testing is needed to confirm the relationship.
Loader, erpt and pgl were also brought into line with the latest official behavior. The ro component now supports NRO files compressed with the LZ4 frame format, expanding the formats that can be handled by the system’s application-loading path.
ZBIC support and bundled homebrew tools
ZBIC compression and decompression has been properly implemented. Applications that rely on ZBIC should now launch and function correctly, addressing a compatibility problem in software that uses that format.
Atmosphère 1.12.2 bundles HBL 2.4.5 and HBMenu 3.6.1, with the project crediting the switchbrew team for those components.
Other project changes carried into 1.12.2
A Dockerfile was added to the Atmosphère project, providing a container configuration for its development workflow. This is primarily relevant to people building or contributing to the project rather than to users running a packaged download.
The R_DISCARD macro was adopted across the codebase where appropriate. The release notes say this completes work begun in version 1.10.0 and removes nodiscard warnings during compilation. General stability improvements are also listed for both 1.12.0 and 1.12.2.
What Atmosphère provides
Atmosphère is work-in-progress customized firmware for the Nintendo Switch. It is made up of several components that replace or modify different parts of the console’s system software; it is not an emulator for another console or a host-platform application.
Its components include Fusée, which loads and validates later firmware stages and applies required patches; Exosphère, a customized TrustZone and secure monitor; Thermosphère, which provides support for virtualized or redirected NAND images; Stratosphère, a collection of custom system modules; and Troposphère, which applies application-level Horizon OS patches.
The 1.12.2 release is therefore most significant for users tracking newer Nintendo Switch system software. It combines the new 23.5.0 compatibility work with the larger 23.0.0 compatibility base, updated low-level behavior, additional module memory and fixes for applications using ZBIC compression.
