---
id: CVE-2026-57843
title: >-
  NetBSD contains an information disclosure vulnerability in mm_open() within
  sys/dev/mm.c that allows unprivileged local users to obtain real kernel
  virtual addresses by opening world-accessible devices such as /dev/null or
  /dev/zero, whi…
summary: >-
  NetBSD contains an information disclosure vulnerability in mm_open() within
  sys/dev/mm.c that allows unprivileged local users to obtain real kernel
  virtual addresses by opening world-accessible devices such as /dev/null or
  /dev/zero, whi…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N'
cwe:
  - CWE-732
vendor: The NetBSD Foundation
product: NetBSD
affected:
  - NetBSD >= 9.0 < 9.5
  - NetBSD >= 10.0 <= 10.1
published: '2026-09-11'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T21:04:40.340'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-57843'
references:
  - url: 'https://gnats.netbsd.org/60373'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/netbsd-mm-open-pk-kmem-flag-kernel-pointer-information-disclosure
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
epss: 0.00145
epssPercentile: 0.03161
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-18T17:12:11.206495Z'
ingestedAt: '2026-09-11T17:50:33.555Z'
---

## Overview

NetBSD contains an information disclosure vulnerability in mm_open() within sys/dev/mm.c that allows unprivileged local users to obtain real kernel virtual addresses by opening world-accessible devices such as /dev/null or /dev/zero, which incorrectly receive the PK_KMEM process flag. Attackers can exploit this misconfigured flag to bypass the CANSEE_KPTR obfuscation mechanism and read kernel virtual addresses for sensitive kernel structures including struct proc, kauth_cred, filedesc, and vmspace via sysctl KERN_PROC queries.

## Remediation

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