{"id":"UBUNTU-CVE-2026-33150","details":"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has been patched in version 3.18.2.","modified":"2026-07-28T21:28:01.034105136Z","published":"2026-03-20T21:17:00Z","withdrawn":"2026-07-28T18:33:22Z","upstream":["CVE-2026-33150"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-33150"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-33150"},{"type":"REPORT","url":"https://github.com/libfuse/libfuse/releases/tag/fuse-3.18.2"},{"type":"REPORT","url":"https://github.com/libfuse/libfuse/security/advisories/GHSA-qxv7-xrc2-qmfx"}],"affected":[{"package":{"name":"fuse3","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/fuse3?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.17.4-1","3.18.1-1","3.18.2-1"],"ecosystem_specific":{"binaries":[{"binary_name":"fuse","binary_version":"3.18.2-1"},{"binary_name":"fuse3","binary_version":"3.18.2-1"},{"binary_name":"libfuse3-4","binary_version":"3.18.2-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-33150.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},{"type":"Ubuntu","score":"medium"}]}