{"api_version":"1","generated_at":"2026-08-19T11:43:50+00:00","cve":"CVE-2026-49429","urls":{"html":"https://cve.report/CVE-2026-49429","api":"https://cve.report/api/cve/CVE-2026-49429.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-49429","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-49429"},"summary":{"title":"Kernel heap overflow in ZFS_IOC_USERSPACE_MANY ioctl","description":"The ZFS_IOC_USERSPACE_MANY ioctl, used by zfs-userspace(8), truncated a 64-bit output buffer size to a 32-bit integer for the kernel allocation, but used the original 64-bit size as the buffer limit when writing records.\n\nA local user with the \"userused\" delegated ZFS permission can trigger a kernel heap overflow via the ZFS_IOC_USERSPACE_MANY ioctl, potentially escalating privileges.","state":"PUBLISHED","assigner":"freebsd","published_at":"2026-08-19 06:17:42","updated_at":"2026-08-19 06:17:42"},"problem_types":["CWE-122","CWE-122 CWE-122: Heap-based Buffer 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Yang, Yizhou Zhao, Ao Wang, Xuewei Feng, Qi Li, and Ke Xu from Tsinghua University using GLM-5.1 from Z.ai"},{"lang":"en","type":"finder","value":"Emmanuel Genier at Quarkslab"}],"datePublic":"2026-06-30T20:00:00.000Z","descriptions":[{"lang":"en","value":"The ZFS_IOC_USERSPACE_MANY ioctl, used by zfs-userspace(8), truncated a 64-bit output buffer size to a 32-bit integer for the kernel allocation, but used the original 64-bit size as the buffer limit when writing records.\n\nA local user with the \"userused\" delegated ZFS permission can trigger a kernel heap overflow via the ZFS_IOC_USERSPACE_MANY ioctl, potentially escalating privileges."}],"problemTypes":[{"descriptions":[{"cweId":"CWE-122","description":"CWE-122: Heap-based Buffer 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overflow in ZFS_IOC_USERSPACE_MANY ioctl","CVE":"CVE-2026-49429","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"49429","Ordinal":"1","NoteData":"The ZFS_IOC_USERSPACE_MANY ioctl, used by zfs-userspace(8), truncated a 64-bit output buffer size to a 32-bit integer for the kernel allocation, but used the original 64-bit size as the buffer limit when writing records.\n\nA local user with the \"userused\" delegated ZFS permission can trigger a kernel heap overflow via the ZFS_IOC_USERSPACE_MANY ioctl, potentially escalating privileges.","Type":"Description","Title":"Kernel heap overflow in ZFS_IOC_USERSPACE_MANY ioctl"}]}}}