NetBSD up to 9.4/10.1 Device Driver sys/dev/mm.c mm_open information disclosure

CVSS Meta Temp Score
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CTI Interest Score
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4.3$0-$5k0.50+

Summaryinfo

A vulnerability, which was classified as problematic, was found in NetBSD up to 9.4/10.1. This affects the function mm_open of the file sys/dev/mm.c of the component Device Driver. The manipulation results in information disclosure. This vulnerability is reported as CVE-2026-57843. The attack requires a local approach. No exploit exists. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in NetBSD up to 9.4/10.1. It has been classified as problematic. Affected is the function mm_open of the file sys/dev/mm.c of the component Device Driver. The manipulation with an unknown input leads to a information disclosure vulnerability. CWE is classifying the issue as CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. This is going to have an impact on confidentiality. CVE summarizes:

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.

The advisory is shared for download at gnats.netbsd.org. This vulnerability is traded as CVE-2026-57843 since 06/25/2026. The exploitability is told to be easy. The attack needs to be approached locally. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1592.

Upgrading to version 9.5 eliminates this vulnerability.

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Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 4.4
VulDB Meta Temp Score: 4.3

VulDB Base Score: 3.3
VulDB Temp Score: 3.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 5.5
CNA Vector (VulnCheck): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Information disclosure
CWE: CWE-200 / CWE-284 / CWE-266
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: NetBSD 9.5

Timelineinfo

06/25/2026 CVE reserved
09/11/2026 +78 days Advisory disclosed
09/11/2026 +0 days VulDB entry created
09/11/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: gnats.netbsd.org
Status: Confirmed

CVE: CVE-2026-57843 (🔒)
GCVE (CVE): GCVE-0-2026-57843
GCVE (VulDB): GCVE-100-402432

Entryinfo

Created: 09/11/2026 16:16
Changes: 09/11/2026 16:16 (77)
Complete: 🔍
Cache ID: 216::103

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