CVE-2026-98725: Linux kernel · nvmet-auth: fix out-of-bounds write in nvmet_auth_challenge()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.2 High.
Data as of 28 Oct 2026, 01:28 UTC
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 18 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
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 ...
References
- ubuntu.com/security/CVE-2026-98725 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98725 (opens in a new tab)
- git.kernel.org/stable/c/fa6778e030bed9841ddcdf96bc7018da9ac03562 (opens in a new tab)
- git.kernel.org/stable/c/9d61131acd742cf97ee64e453383e41b46568513 (opens in a new tab)
- git.kernel.org/stable/c/8a9b4c0eef19c207663c1ee888257307c869ca86 (opens in a new tab)
- git.kernel.org/stable/c/7fd3c363eba4f2aceb4b3f31cd1cf65e0dcbaee4 (opens in a new tab)