CVE-2026-98725 nvmet-auth: fix out-of-bounds write in nvmet_auth_challenge()
An out-of-bounds write in the Linux kernel NVMe target authentication allows remote attackers to cause a denial of service or potentially execute code.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-98725?
CVE-2026-98725 is a memory corruption vulnerability in Linux, published on 18 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
nvmet-auth: fix out-of-bounds write in nvmet_auth_challenge()
nvmet_auth_challenge() receives its output buffer as a void pointer. sizeof(*d) therefore evaluates to one with GCC and undercounts the fixed challenge header by 15 bytes. A short AUTH_RECEIVE buffer can pass the check before the challenge is copied past the end of its allocation.
Use the typed challenge pointer when calculating the response size.
BUG: KASAN: slab-out-of-bounds in nvmet_execute_auth_receive (drivers/nvme/target/fabrics-cmd-auth.c:442 drivers/nvme/target/fabrics-cmd-auth.c:569) Write of size 32 by task kworker/1:1H/64 Workqueue: nvmet_tcp_wq nvmet_tcp_io_work Call Trace: nvmet_execute_auth_receive (drivers/nvme/target/fabrics-cmd-auth.c:442 drivers/nvme/target/fabrics-cmd-auth.c:569) nvmet_tcp_try_recv_pdu (drivers/nvme/target/tcp.c:1119 drivers/nvme/target/tcp.c:1243) nvmet_tcp_io_work (drivers/nvme/target/tcp.c:1350 drivers/nvme/target/tcp.c:1382 drivers/nvme/target/tcp.c:1445) process_one_work (kernel/workqueue.c:3322) worker_thread (kernel/workqueue.c:3405 kernel/workqueue.c:3486) kthread (kernel/kthread.c:436) ret_from_fork (arch/x86/kernel/process.c:158) ret_from_fork_asm (arch/x86/entry/entry_64.S:245) The buggy address is located 16 bytes inside of allocated 33-byte region [ffff888000554e80, ffff888000554ea1) Kernel panic - not syncing: KASAN: panic_on_warn set ...
Which versions are affected by CVE-2026-98725?
How do I fix CVE-2026-98725?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-98725 being exploited?
There is no known exploitation of CVE-2026-98725 in the wild and no public exploit code.
Sources
Also known as AZL-109118, BELL-CVE-2026-98725, DEBIAN-CVE-2026-98725, GHSA-h488-w8xm-x8gw, UBUNTU-CVE-2026-98725.