---
id: CVE-2026-89700
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  nfsd: validate sockaddr length per family in listener_set

  nfsd_sock_nl_policy declares NFSD_A_SOCK_ADDR as a bare NLA_BINARY
  attribute with no minimum length
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  nfsd: validate sockaddr length per family in listener_set

  nfsd_sock_nl_policy declares NFSD_A_SOCK_ADDR as a bare NLA_BINARY
  attribute with no minimum length. A CAP_NE…
severity: medium
cvss: 4.7
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:H'
cwe:
  - CWE-125
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 16a471177496c8e04a9793812c187a2c1a2192fa <
    bf85a0f1e45258f90ceeec14772b5769697dfd75
  - >-
    Linux >= 16a471177496c8e04a9793812c187a2c1a2192fa <
    2aca70c18c5f5d06004122861fb151d5fcc57faf
  - >-
    Linux >= 16a471177496c8e04a9793812c187a2c1a2192fa <
    22d0e4752ca88fd84196d22ebeedc905e6540440
  - >-
    Linux >= 16a471177496c8e04a9793812c187a2c1a2192fa <
    bdcc85c2b05a9378d8bd2d65f9fc41440a3cf464
  - Linux 6.10
published: '2026-09-11'
updated: '2026-09-21'
sourceUpdated: '2026-09-21T14:17:25.580'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89700'
references:
  - url: 'https://git.kernel.org/stable/c/22d0e4752ca88fd84196d22ebeedc905e6540440'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/2aca70c18c5f5d06004122861fb151d5fcc57faf'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/bdcc85c2b05a9378d8bd2d65f9fc41440a3cf464'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/bf85a0f1e45258f90ceeec14772b5769697dfd75'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89700.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89700'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532454'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89700'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89700'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89700.mbox
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00168
epssPercentile: 0.06451
cvssSource: vendor
ingestedAt: '2026-09-14T11:11:19.885Z'
---

## Overview

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

nfsd: validate sockaddr length per family in listener_set

nfsd_sock_nl_policy declares NFSD_A_SOCK_ADDR as a bare NLA_BINARY
attribute with no minimum length. A CAP_NET_ADMIN caller can send a
16-byte NFSD_A_SOCK_ADDR with sa_family=AF_INET6, causing a 12-byte
OOB read across three consumers (rpc_cmp_addr_port, svc_find_listener,
kernel_bind).

nfsd_nl_listener_set_doit() also parsed and validated each listener
entry inline in two separate loops, interleaved with mutating the
running listener configuration. The validation was duplicated, used an
open-coded "nla_len < sizeof(struct sockaddr)" check that was too short
for AF_INET6, and handled a malformed entry inconsistently depending on
which loop noticed it.

Add an nfsd_nl_validate_listeners() helper that walks the entire list
once and confirms each entry parses, carries both an address and a
transport name, and is long enough for its address family
(sizeof(struct sockaddr_in) for AF_INET, sizeof(struct sockaddr_in6)
for AF_INET6, -EAFNOSUPPORT otherwise). Call it before taking
nfsd_mutex or creating the serv, so a malformed request fails cleanly
with no side effects.

Since every entry is known valid by the time the two existing loops
run, drop the redundant presence and per-family length checks from
both, leaving only the nla_parse_nested() call needed to extract the
data.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89700.json)