{"id":"CVE-2026-33150","state":"PUBLISHED","title":"Use After Free in libfuse","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. 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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":[{"vendor":"libfuse","product":"libfuse","versions":[{"version":">= 3.18.0, < 3.18.2","status":"affected"}]}],"references":[{"url":"https://github.com/libfuse/libfuse/security/advisories/GHSA-qxv7-xrc2-qmfx","name":"https://github.com/libfuse/libfuse/security/advisories/GHSA-qxv7-xrc2-qmfx","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/libfuse/libfuse/commit/49fcd891a58f622c098e2ca67d66086f7b213836","name":"https://github.com/libfuse/libfuse/commit/49fcd891a58f622c098e2ca67d66086f7b213836","tags":["x_refsource_MISC"]},{"url":"https://github.com/libfuse/libfuse/releases/tag/fuse-3.18.2","name":"https://github.com/libfuse/libfuse/releases/tag/fuse-3.18.2","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"LOCAL","availabilityImpact":"HIGH","baseScore":7.8,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-416","lang":"en","description":"CWE-416: Use After Free","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-03-20T20:20:29.963Z"},"source":{"advisory":"GHSA-qxv7-xrc2-qmfx","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-26T00:00:00+00:00","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3","id":"CVE-2026-33150"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-03-27T03:55:40.426Z"}},{"title":"libfuse: libfuse: Arbitrary code execution via use-after-free in io_uring subsystem","descriptions":[{"lang":"en","value":"A flaw was found in libfuse. A use-after-free vulnerability in the io_uring subsystem allows a local attacker to potentially execute arbitrary code and crash FUSE (Filesystem in Userspace) filesystem processes. This occurs when io_uring thread creation fails due to resource exhaustion, such as limits imposed by cgroup pids.max, causing a dangling pointer to be stored and later used during session shutdown. This vulnerability is reliably triggered in containerized environments."}],"affected":[{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 7","packageName":"fuse","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:7"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 8","packageName":"fuse-sshfs","defaultStatus":"affected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:8"]}],"references":[{"url":"https://access.redhat.com/security/cve/CVE-2026-33150","tags":["vdb-entry","x_refsource_REDHAT"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2449771","name":"RHBZ#2449771","tags":["issue-tracking","x_refsource_REDHAT"]},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33150.json","tags":["x_sadp-csaf-vex"]}],"metrics":[{"other":{"content":{"namespace":"https://access.redhat.com/security/updates/classification/","value":"Important"},"type":"Red Hat severity rating"}},{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"LOCAL","availabilityImpact":"HIGH","baseScore":7.8,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"format":"CVSS"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-825","description":"Expired Pointer Dereference","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"redhat-SADP","orgId":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c","dateUpdated":"2026-07-15T01:07:15.081Z"},"datePublic":"2026-03-20T20:20:29.963Z","timeline":[{"lang":"en","time":"2026-03-20T21:01:20.625Z","value":"Reported to Red Hat."},{"lang":"en","time":"2026-03-20T20:20:29.963Z","value":"Made public."}],"x_adpType":"supplier","x_generator":{"engine":"sadp-cli 1.0.0"}}]}}}