{"api_version":"1","generated_at":"2026-09-11T23:53:29+00:00","cve":"CVE-2026-80946","urls":{"html":"https://cve.report/CVE-2026-80946","api":"https://cve.report/api/cve/CVE-2026-80946.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-80946","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-80946"},"summary":{"title":"fuse: copy request headers via a stack buffer for io-uring","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.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-11 20:19:00","updated_at":"2026-09-11 20:19:00"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/fd10f40af314f07b6d6e028b1ca25c8b49903aab","name":"https://git.kernel.org/stable/c/fd10f40af314f07b6d6e028b1ca25c8b49903aab","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/194d0fb0ea4720535ff3168c9d04c7632cec7071","name":"https://git.kernel.org/stable/c/194d0fb0ea4720535ff3168c9d04c7632cec7071","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a47a416ff68d706dc3327ab583f86b9ee757358b","name":"https://git.kernel.org/stable/c/a47a416ff68d706dc3327ab583f86b9ee757358b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-80946","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80946","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected c090c8abae4b6b77a1bee116aa6c385456ebef96 194d0fb0ea4720535ff3168c9d04c7632cec7071 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected c090c8abae4b6b77a1bee116aa6c385456ebef96 a47a416ff68d706dc3327ab583f86b9ee757358b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected c090c8abae4b6b77a1bee116aa6c385456ebef96 fd10f40af314f07b6d6e028b1ca25c8b49903aab git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.14","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.14 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.51 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.4 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/fuse/dev_uring.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"194d0fb0ea4720535ff3168c9d04c7632cec7071","status":"affected","version":"c090c8abae4b6b77a1bee116aa6c385456ebef96","versionType":"git"},{"lessThan":"a47a416ff68d706dc3327ab583f86b9ee757358b","status":"affected","version":"c090c8abae4b6b77a1bee116aa6c385456ebef96","versionType":"git"},{"lessThan":"fd10f40af314f07b6d6e028b1ca25c8b49903aab","status":"affected","version":"c090c8abae4b6b77a1bee116aa6c385456ebef96","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/fuse/dev_uring.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.14"},{"lessThan":"6.14","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.51","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.4","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.51","versionStartIncluding":"6.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.4","versionStartIncluding":"6.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"6.14","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"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."}],"providerMetadata":{"dateUpdated":"2026-09-11T19:42:17.576Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/194d0fb0ea4720535ff3168c9d04c7632cec7071"},{"url":"https://git.kernel.org/stable/c/a47a416ff68d706dc3327ab583f86b9ee757358b"},{"url":"https://git.kernel.org/stable/c/fd10f40af314f07b6d6e028b1ca25c8b49903aab"}],"title":"fuse: copy request headers via a stack buffer for io-uring","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-80946","datePublished":"2026-09-11T19:42:17.576Z","dateReserved":"2026-08-26T14:34:25.803Z","dateUpdated":"2026-09-11T19:42:17.576Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-11 20:19:00","lastModifiedDate":"2026-09-11 20:19:00","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"80946","Ordinal":"1","Title":"fuse: copy request headers via a stack buffer for io-uring","CVE":"CVE-2026-80946","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"80946","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"fuse: copy request headers via a stack buffer for io-uring"}]}}}