cbcvebase.
CVE-2026-64320
published 2026-07-25

CVE-2026-64320: In the Linux kernel, the following vulnerability has been resolved: nvmet: fix pre-auth out-of-bounds heap read in Discovery Get Log Page…

PriorityP354critical9.1CVSS 3.1
AVNACLPRNUINSUCHINAH
EPSS
0.75%
53.6th percentile
In the Linux kernel, the following vulnerability has been resolved: nvmet: fix pre-auth out-of-bounds heap read in Discovery Get Log Page nvmet_execute_disc_get_log_page() validates only the dword alignment of the host-supplied Log Page Offset (lpo). The 64-bit offset is then added to a small kzalloc'd buffer that holds the discovery log page and the result is passed straight to nvmet_copy_to_sgl(), which memcpy()s data_len bytes out to the host with no source-side bound check: u64 offset = nvmet_get_log_page_offset(req->cmd); /* 64-bit host */ size_t data_len = nvmet_get_log_page_len(req->cmd); /* 32-bit host */ ... if (offset & 0x3) { ... } /* only check */ ... alloc_len = sizeof(*hdr) + entry_size * discovery_log_entries(req); buffer = kzalloc(alloc_len, GFP_KERNEL); ... status = nvmet_copy_to_sgl(req, 0, buffer + offset, data_len); The Discovery controller is unauthenticated -- nvmet_host_allowed() returns true unconditionally for the discovery subsystem -- so the call is reachable pre-authentication by any TCP/RDMA/FC peer that can reach the nvmet target. With a discovery log page of ~1 KiB, an attacker requesting up to 4 KiB starting at offset == alloc_len reads the next slab page out and gets its content returned over the fabric (an empirical run on a default nvmet-tcp loopback target leaked 81 canonical kernel pointers in one Get Log Page response). Pointing the offset at unmapped kernel memory faults the in-kernel memcpy and crashes (or panics, on panic_on_oops=1) the target host instead. The attacker-controlled source-side offset pattern "nvmet_copy_to_sgl(req, 0, buffer + ATTACKER_OFFSET, ...)" is unique to nvmet_execute_disc_get_log_page in the entire nvmet codebase: every other Get Log Page handler in admin-cmd.c either ignores lpo (and silently starts every response at offset 0) or tracks a local destination offset with a fixed source pointer. Validate the host-supplied offset against the log page size, cap the copy length to what is actually ava

Affected

27 ranges· showing 25
VendorProductVersion rangeFixed in
linuxlinux——
linuxlinux>= a07b4970f464f13640e28e16dad6cfa33647cc99 < 33b974eb626154ae9348f2bac7de84cb2a3d9dd433b974eb626154ae9348f2bac7de84cb2a3d9dd4
linuxlinux>= a07b4970f464f13640e28e16dad6cfa33647cc99 < 56c021a0869260d04c4b65d1471936aaf917711456c021a0869260d04c4b65d1471936aaf9177114
linuxlinux>= a07b4970f464f13640e28e16dad6cfa33647cc99 < a29b316b9bbfd269f323ab4ba9906a894025680fa29b316b9bbfd269f323ab4ba9906a894025680f
linuxlinux>= a07b4970f464f13640e28e16dad6cfa33647cc99 < 53cd102a7a56079b11b897835bd9b94c14e6322c53cd102a7a56079b11b897835bd9b94c14e6322c
linuxlinux_kernel——
linuxlinux_kernel>= 4.8 < 6.12.966.12.96
linuxlinux_kernel>= 6.13 < 6.18.396.18.39
linuxlinux_kernel>= 6.19 < 7.1.47.1.4
ubuntulinux——
ubuntulinux-aws——
ubuntulinux-aws-7.0——
ubuntulinux-azure——
ubuntulinux-azure-7.0——
ubuntulinux-gcp——
ubuntulinux-gcp-7.0——
ubuntulinux-gke——
ubuntulinux-hwe-7.0——
ubuntulinux-ibm——
ubuntulinux-nvidia-7.0——
ubuntulinux-nvidia-bos——
ubuntulinux-nvidia-tegra——
ubuntulinux-oem-7.0——
ubuntulinux-oracle——
ubuntulinux-oracle-7.0——

CVSS provenance

nvdv3.19.1CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
vendor_redhat9.1CRITICAL
vendor_ubuntu9.1CRITICAL
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