CVE-2026-89691

Last refreshed2026-10-19

Status: UPDATED | Advisory ID: CVE-2026-89691

Key Details

CVE	CVE-2026-89691
CVSS Score / Version	7.1 (High) / CVSS v3.1
Updated	2026-10-19
CVSS Vector	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H`
CVSS Prose	attack vector is local; attack complexity is low; privileges required is low; user interaction is none; scope is unchanged; confidentiality impact is high; integrity impact is none; availability impact is high.
Affected products	Linux Kernel

Vendor	Product	Affected Versions	Patch Status
Linux	Linux Kernel

Vendor

Product

Affected Versions

Patch Status

Linux

Linux Kernel

Subsystems	OT Supporting Infrastructure
Sectors	All Sectors

In the Linux kernel, the following vulnerability has been resolved:

nfsd: clear opcnt on compound arg release to prevent OOB read

nfsd4_release_compoundargs() resets args->ops to the inline iops[8]

array when the dynamically-allocated ops buffer is freed, but leaves

args->opcnt at its original value (which can be up to 200 for NFSv4.1+

compounds).

If rq_status_counter is stuck at an odd value (which can happen when

nfsd_dispatch() hits an error path after setting it odd), the RPC

status dumpit handler reads min(opcnt, 16) entries from args->ops[].

Since iops only has 8 elements and is the last field in struct

nfsd4_compoundargs, reading indices 8-15 accesses adjacent slab memory

and leaks it to userspace via netlink.

Zero opcnt unconditionally in nfsd4_release_compoundargs() so stale

compound metadata is never exposed through the status interface.

[ cel: Remove the kvfree_rcu_mightsleep() sleep from the exposure window ] (NVD)

Monitor Linux's web page for any future patch releases.

Source	Reference
NVD	https://nvd.nist.gov/vuln/detail/CVE-2026-89691
CVE	https://www.cve.org/CVERecord?id=CVE-2026-89691

Source

Reference

NVD

CVE