Vulnerability · Published Sep 11, 2026 · Assigned by VulnCheck

CVE-2026-57843NetBSD mm_open() PK_KMEM Flag Kernel Pointer Information Disclosure

Medium 5.5

In plain English

A medium-severity incorrect permission assignment in NetBSD from The NetBSD Foundation. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 4% of all known vulnerabilities).

Severity (CVSS 3.1)5.5Medium

Exploit odds (30 days)0.1%top 96.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
The NetBSD Foundation	NetBSD	9.0 – before 9.510.0 – through 10.1

Weakness: CWE-732 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

References

Patch Commit vendor-advisory, patch
https://www.vulncheck.com/advisories/netbsd-mm-open-pk-kmem-flag-kernel-pointer-information-disclosure third-party-advisory