Description
libfuse is the reference implementation of the Linux FUSE. From version 3.18.0 to before version 3.18.2, a use-after-free vulnerability in the io_uring subsystem of libfuse allows a local attacker to crash FUSE filesystem processes and potentially execute arbitrary code. When io_uring thread creation fails due to resource exhaustion (e.g., cgroup pids.max), fuse_uring_start() frees the ring pool structure but stores the dangling pointer in the session state, leading to a use-after-free when the session shuts down. The trigger is reliable in containerized environments where cgroup pids.max limits naturally constrain thread creation. This issue has been patched in version 3.18.2.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| 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.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | fuse3 | 3.18.2-1 | — |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
GitHub 1 repository
-
abhinavagarwal07/abhinavagarwal07.github.io ★ 0 · Mar 25, 2026
RingWraith: CVE-2026-33150 and CVE-2026-33179 — Use-After-Free and NULL Dereference in libfuse io_uring
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 1
- WID-SEC-2026-0913 Red Hat FUSE (libfuse): Mehrere Schwachstellen ermöglichen Codeausführung und DoS BSI CERT-Bund (WID) · Apr 19, 2026