CVE-2026-33179 PUBLISHED

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

Assigner: GitHub_M
Reserved: 17.03.2026 Published: 20.03.2026 Updated: 20.03.2026

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.

Metrics

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CVSS Score: 5.5

Product Status

Vendor libfuse
Product libfuse
Versions
  • Version >= 3.18.0, < 3.18.2 is affected

References

Problem Types

  • CWE-476: NULL Pointer Dereference CWE