VulnerabilityPublished 18 Oct 2026Updated 21 Oct 2026

CVE-2026-98725: Linux kernel · nvmet-auth: fix out-of-bounds write in nvmet_auth_challenge()

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in fa6778e030bed9841ddcdf96bc7018da9ac03562 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 14:18 UTC

Severity

Unrated

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.2% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in fa6778e030bed9841ddcdf96bc7018da9ac03562, ef4dfad231a787aded76e5b03788ddb18c8aebab, 9d61131acd742cf97ee64e453383e41b46568513 +2

Exploitation 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.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ db1312dd95488b5e6ff362ff66fcf953a46b1821, < fa6778e030bed9841ddcdf96bc7018da9ac03562	Fixed in fa6778e030bed9841ddcdf96bc7018da9ac03562
LinuxLinux	Affected ≥ db1312dd95488b5e6ff362ff66fcf953a46b1821, < ef4dfad231a787aded76e5b03788ddb18c8aebab	Fixed in ef4dfad231a787aded76e5b03788ddb18c8aebab
LinuxLinux	Affected ≥ db1312dd95488b5e6ff362ff66fcf953a46b1821, < 9d61131acd742cf97ee64e453383e41b46568513	Fixed in 9d61131acd742cf97ee64e453383e41b46568513
LinuxLinux	Affected ≥ db1312dd95488b5e6ff362ff66fcf953a46b1821, < 8a9b4c0eef19c207663c1ee888257307c869ca86	Fixed in 8a9b4c0eef19c207663c1ee888257307c869ca86
LinuxLinux	Affected ≥ db1312dd95488b5e6ff362ff66fcf953a46b1821, < 7fd3c363eba4f2aceb4b3f31cd1cf65e0dcbaee4	Fixed in 7fd3c363eba4f2aceb4b3f31cd1cf65e0dcbaee4
LinuxLinux	Affected =6.0	Fixed in–

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

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