{"cve":"CVE-2026-80946","nvd":{"published":"2026-09-11T20:19:00.180","modified":"2026-10-19T09:17:25.933","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfuse: copy request headers via a stack buffer for io-uring\n\nThe fuse-io-uring transport copies req->in.h out to the ring in\nfuse_uring_copy_to_ring() and req->out.h back in fuse_uring_commit().\nBoth headers live inside the fuse_request slab object, whose cache\n(fuse_req_cachep) is created without a usercopy whitelist, so copying\nthem directly to/from userspace trips CONFIG_HARDENED_USERCOPY and\npanics:\n\n  usercopy: Kernel memory exposure attempt detected from SLUB object\n  'fuse_request' (offset 56, size 40)!\n  kernel BUG at mm/usercopy.c:102!\n  Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI\n  RIP: 0010:usercopy_abort (mm/usercopy.c:90)\n  Call Trace:\n   __check_heap_object (mm/slub.c:8268)\n   __check_object_size (mm/usercopy.c:197 mm/usercopy.c:258 mm/usercopy.c:223)\n   copy_header_to_ring (fs/fuse/dev_uring.c:618)\n   fuse_uring_prepare_send (fs/fuse/dev_uring.c:776 fs/fuse/dev_uring.c:785)\n   fuse_uring_send_in_task (fs/fuse/dev_uring.c:1306)\n   tctx_task_work_run (io_uring/tw.c:96)\n   task_work_run (kernel/task_work.c:233)\n   io_run_task_work (io_uring/tw.h:84)\n   io_cqring_wait (io_uring/wait.c:278)\n   __do_sys_io_uring_enter (io_uring/io_uring.c:2685)\n   entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)\n\nBounce both headers through an on-stack copy so the usercopy touches\nstack memory, not the slab object.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/194d0fb0ea4720535ff3168c9d04c7632cec7071","https://git.kernel.org/stable/c/a47a416ff68d706dc3327ab583f86b9ee757358b","https://git.kernel.org/stable/c/fd10f40af314f07b6d6e028b1ca25c8b49903aab"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:53:43.293028046+00:00"},"epss":{"cve":"CVE-2026-80946","score":0.00166,"percentile":0.05797,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}