General

• Update build process to use Xcode 26.0.1 (macOS 26.0 SDK)

• Update Installer package to use absolute paths when invoking command line tools in thepostinstall script

• Replacetypeof with the__typeof__ builtin inlibfuse3 headers. Thetypeof keyword is part of the C23 ISO standard, but is not officially supported in older C ISO standards.

• Drop compatibility code for macOS 11 and earlier. macFUSE 5 supports macOS 12 through macOS 26.

• Fix license file formatting. On macOS 26, QuickLook fails to render lists correctly if they are placed inside table cells in rich text documents.

Kernel Backend

• Preserve a vnode's identity when marking it as dangling. Resetting the identity causes thefchmod(2) system call to fail. This addresses#1112.

• Resolve symbolic links in the kernel extension path before attempting to load the kernel extension

FSKit Backend

• Improve support for macOS 26.FSClient now provides information about installed third party file system extensions, enabling more reliable detection of whether a file system extension has been enabled by the user.

• Add support for creating a mount point in/Volumes automatically when mounting a volume

• Introduce foundational changes in preparation for new FSKit features in macFUSE 5.1

• Fix bug inmacFUSE.framework that could result in the file system process crashing after a failed mount attempt. The bug was introduces in version 4.10.0.

• Updatelibfuse3 to version 3.17.4

• Use macOS 26.0 SDK instead of macOS 15.5 SDK to build macFUSE

• Introduced foundational changes in preparation for new FSKit features in macFUSE 5.1

• Fix crash inmacFUSE.framework after unmounting a volume. The bug has been introduced in version 5.0.0 and was caused by over-releasing an object on the mount thread. For details, see#1086.

• Improve compatibility with macOS 26. macOS 26 reports itself as macOS 16 for binaries that were built using the macOS 15 SDK. This affected the updater.

• Fix rare kernel panic when re-parenting "dangling" vnodes. Dangling vnodes were removed from the file hierarchy, but each retained a reference to its previous parent directory. This could trigger a kernel panic under certain conditions. For details, see#1085.

• Add support for updating the bundled Launch Services when mounting a volume.

• Add--force option to re-install the bundled Launch Services even though they are already up to date.

• Add support for macOS 26

• Add support for Xcode 26

• Fix Unicode normalization bug. UseICU instead oficonv to normalize file names. Usingiconv() is not a viable option, as the version bundled with macOS lacks support for the full range of Unicode characters (emojis). For details, see#1077.

• Switch from App Services to Launch Services. This change streamlines the installation process and eliminates the need for users to authenticate as admin when using theFSKit backend for the first time.

• Address compatibility issue withlibfuse3 API extensions. Theino64_t type may be unavailable when_POSIX_C_SOURCE is defined. For details, see#1080.

• Drop support for macOS 11. macOS 12 is the first macOS release that supports Swift Concurrency natively.

• Use macOS 15.5 SDK instead of macOS 15.4 SDK to build macFUSE

• Update uninstaller to remove new Launch Services

• Updatelibfuse3 to version 3.17.2

• Fix an issue that could cause a crash of the file system process on failed mount attempts

  When mounting a volume, the file system process expects to receive a socket handle for exchanging FUSE messages. Sending the mount status code without sending a socket handle first, can result in a crash. This issue only affected theFSKit backend. For details, see#1071.

• Address an issue that could result in the file system extension not being listed in System Settings

  In some casesPluginKit fails to discover the file system extension automatically. As a workaround we register the extension explicitly. This issue only affected theFSKit backend. For details, see#1071.

• Optimize the service that is responsible for brokering connections between the file system extension and file system processes

• Update uninstaller for macFUSE 5

• Update build script and add target build options--no-default and--no-inherit

• Add experimental support forFSKit on macOS 15.4 and newer releases of macOS

  macFUSE supports two backends for mounting file systems. By default, the legacy VFS kernel API is used to mount volumes. When specifying the mount-time option-o backend=fskit, macFUSE will useFSKit to mount the file system. For more information, seeFUSE Backends.

• Drop support for macOS 10.9 to 10.15. macFUSE 5 supports macOS 11 and later versions of macOS.

• MakemacFUSE.framework swift-friendlier by adding generics and nullability annotations

• Add newmacFUSE.framework delegate method for listing directories. The new delegate method supports returning directory entries including the name and the requested attributes of each entry. This is the first step in implementing support forFUSE_READDIRPLUS.

  - (nullable NSArray<GMDirectoryEntry *> *)    contentsOfDirectoryAtPath:(NSString *)path   includingAttributesForKeys:(NSArray<NSString *> *)keys                        error:(NSError * _Nullable * _Nonnull)error

• Update reference file systems for macFUSE 5. For more information, see thedemo repository.

• Optimize build script

• Invalidate a vnode's identity in case the corresponding file is removed.

  When performing a remove operation, the file might not actually be removed by the user space code.libfuse renames open files, hides them and defers removing them until all open file handles have been closed (unlesshard_remove is enabled). This means we might come across the vnode again, e.g. while performing areaddir(3) operation. We need to invalidate the vnode's current identity to make sure Finder does not display any outdated information.

• Optimize build script

• Updatelibfuse3 to version 3.17.1

  Some macOS specific features require FUSE API extensions that break compatibility with the vanilla FUSE API. Setting the compile-time flagFUSE_DARWIN_ENABLE_EXTENSIONS to 0, when building a file system, disables those API extensions. By default, the macOS specific API extensions are enabled.

  Please note:

  • The macOS specificlibfuse3 API extensions might not be stable, yet. This means thatlibfuse3 file systems that are built for macFUSE 4.10.1 might need to be updated to work with future macFUSE releases.

• Add support for arbitrary file system block sizes

  The macOS kernel imposes no restrictions on the block size of a file system, neither should we. macFUSE supports file system block sizes between 128 B and 1 MB. The specified I/O size (-oiosize=...) is rounded down to the next multiple of the file system block size, if necessary.

  The device block size (-oblocksize=...) needs to be a power of two and may not exceed 4 KB on Intel Macs and 16 KB Apple Silicon Macs.

• Address code signing issue. The bundled download helperksurl needs to be code signed individually to make its origin transparent. In previous releases,ksurl was only code signed indirectly as component of the update tool. For details, see#1062.

• Declare the maximum size of extended attributes.pathconf(..., _PC_XATTR_SIZE_BITS) returns the number of bits that are required to store the maximum extended attribute size in bytes, in our case 25, which equals a maximum extended attribute size of 33,554,431 bytes (~ 32 MB).