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OpenAdvisories
Medium · 5.5 CVE-2026-33179 EUVD-2026-13794

libfuse: NULL Pointer Dereference and Memory Leak in io_uring Queue Initialization

Published Mar 20, 2026 · Updated Mar 25, 2026 · Assigned by GitHub_M

Description

libfuse is the reference implementation of the Linux FUSE. From version 3.18.0 to before version 3.18.2, a NULL pointer dereference and memory leak in fuse_uring_init_queue allows a local user to crash the FUSE daemon or cause resource exhaustion. When numa_alloc_local fails during io_uring queue entry setup, the code proceeds with NULL pointers. When fuse_uring_register_queue fails, NUMA allocations are leaked and the function incorrectly returns success. Only the io_uring transport is affected; the traditional /dev/fuse path is not affected. PoC confirmed with AddressSanitizer/LeakSanitizer. This issue has been patched in version 3.18.2.

Affected products

VendorProductAffectedFixed
libfuse libfuse >= 3.18.0, < 3.18.2 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 fuse3 3.18.2-1 —

Advisories 1

References