NULL pointer dereference in Libfuse
CVE-2026-33179
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.002 (5.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 5th percentile — 5.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: -0.000
Affected products
- Libfuse — versions >= 3.18.0, < 3.18.2
- Libfuse Project
Weakness classification (CWE)
References
- github.com/libfuse/libfuse/security/advisories/GHSA-x669-v3mq-r358 (Vendor Advisory)
- github.com/libfuse/libfuse/commit/7beb86c09b6ec5aab14dc25256ed8a5ad18554d7 (Patch)
- github.com/libfuse/libfuse/releases/tag/fuse-3.18.2 (Product, Release Notes)
Frequently asked questions
- What is CVE-2026-33179?
- CVE-2026-33179 is a medium-severity vulnerability in Libfuse, classified under NULL Pointer Dereference. CVSS score: 5.5/10. Published 2026-03-20.
- How severe is CVE-2026-33179?
- Medium severity. CVSS v3 base score is 5.5 out of 10.