CVE-2026-64320
CriticalCVSS 9.1Exploitation Probability (EPSS)
Elevated risk52th percentile - higher than 52% of all known CVEs
Summary
A vulnerability in the Linux kernel's nvmet_execute_disc_get_log_page() function allows an unauthenticated attacker to perform an out-of-bounds heap read when processing a Discovery Get Log Page request. Missing validation of offset and data length can lead to kernel memory leak or system panic.
Risk Assessment
An attacker can remotely, without authentication, read kernel memory (e.g., pointers) or cause a kernel panic, leading to information disclosure or denial of service.
Recommendation
Immediately update the Linux kernel to a version containing the fix that validates offset and data length and zero-fills the remaining response buffer.
Other vulnerabilities in Linux kernel
See all- CVE-2026-90049Unknown
In the Linux kernel, a vulnerability in skb_zerocopy() was fixed: it incorrectly called skb_tx_error() on the source skb when copying frags. This completed the zerocopy uarg and cleared the SKBFL_SHARED_FRAG flag on an skb still in use by the network stack. Specifically on the OVS_ACTION_ATTR_USERSPACE path, the skb was not freed on error, which could lead to ESP data being decrypted in place where the skb did not privately own frags, potentially causing data corruption or other issues.
- CVE-2026-90046Unknown
In the Linux kernel, free_pages_nolock() uses spin_trylock() in NMI context on uniprocessor (UP) systems, which is unsafe. The bug affects the page freeing path and can crash the kernel. It is likely exploitable by local attackers for privilege escalation.
- CVE-2026-90045Unknown
In the Linux kernel USB gadget ffs driver, the io_data structure stores a pointer to the submitting task's mm_struct but does not hold a reference while async requests are pending. This can cause a use-after-free if the task exits before completion handling finishes. The fix takes a reference with mmgrab() when queuing and releases it with mmdrop() on completion.
- CVE-2026-90044Unknown
In the Linux kernel USB gadget f_fs driver, a use-after-free exists in the AIO error path. When ffs_epfile_io() fails with an error other than -EIOCBQUEUED, the io_data structure is freed, but the kiocb cancel function remains armed and points to the freed pointer. A concurrent cancel (e.g., sys_io_cancel()) can cause a use-after-free. The fix safely disarms the cancellation via kiocb->ki_complete() and returns -EIOCBQUEUED.
- CVE-2026-90043Unknown
In the Linux kernel zram module, the slot lock bit is set in the wrong position on 64-bit big-endian systems. Instead of landing in the flags field, it lands in ac_time, so with ZRAM_TRACK_ENTRY_ACTIME enabled, storing the access time wipes out the held lock bit and lets another CPU take the same slot lock. An access time value with that bit set can make the slot appear locked forever. The fix shifts the lock bit into the flags half on big-endian 64-bit.
- CVE-2026-90042Unknown
A vulnerability was found in the Linux kernel's Ceph filesystem where ceph_fname_to_usr() passed vmalloc() buffers to the fscrypt crypto API, which requires linear memory. This can cause kernel oopses, especially on non-x86 platforms. The fix adds support for vmalloc() buffers using a bounce buffer.
- CVE-2026-90041Unknown
In the Linux kernel, the HID sony driver fails to remove a controller from the device list when HID core input device registration fails. The devres-managed sony_sc is freed while its list node remains linked, leading to use-after-free when the next matching controller is handled.
- CVE-2026-90039Unknown
In the Linux kernel, NFSD admin state-revocation handlers (unlock_filesystem, NFSD_CMD_UNLOCK_FILESYSTEM, NFSD_CMD_UNLOCK_EXPORT) only check nn->nfsd_serv, which is set before nn->conf_id_hashtbl is allocated. This leads to a NULL dereference when the server has not yet started.
- CVE-2026-90038Unknown
In the Linux kernel, nfsd4_revoke_export_states() drops nn->client_lock but the held stateid reference does not pin the client. A concurrent client teardown can free the client while revoke_one_stid() still dereferences it, causing a use-after-free.
- CVE-2026-90037Unknown
In the Linux kernel, an nfs4_openowner left on nn->close_lru holds only a raw pointer to its nfs4_client. When the laundromat reaps entries, drops client_lock and calls nfs4_put_stid(), a concurrent force_expire_client() can free the client, causing a use-after-free.
Original NVD description (English source)
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 available, and zero-fill any remainder of the host transfer buffer. The zero-fill matches the existing short-response pattern in nvmet_execute_get_log_changed_ns() (admin-cmd.c) and prevents leaking transport SGL contents when the host asks for more bytes than the log page contains.