CVE-2026-57843: The Netbsd Foundation Netbsd

Medium severity, CVSS 5.5. EPSS: 0.1% chance of exploitation in the next 30 days.

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

• The Netbsd Foundation Netbsd: from 9.0, before 9.5 (fixed in 9.5); from 10.0, up to and including 10.1

Published 2026-09-11. Last modified 2026-09-24.