CVE-2026-33150
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.31%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.31% probability · 24th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-416, CWE-825
- Affected
- libfuse project/libfuse
- Source
- security-advisories@github.com
References
- https://github.com/libfuse/libfuse/commit/49fcd891a58f622c098e2ca67d66086f7b213836Patch
- https://github.com/libfuse/libfuse/releases/tag/fuse-3.18.2Product, Release Notes
- https://github.com/libfuse/libfuse/security/advisories/GHSA-qxv7-xrc2-qmfxVendor Advisory
- https://access.redhat.com/security/cve/CVE-2026-33150
- https://bugzilla.redhat.com/show_bug.cgi?id=2449771
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33150.json
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.