CVE-2026-57843 NetBSD mm_open() PK_KMEM Flag Kernel Pointer Information Disclosure
Unprivileged local users can leak kernel virtual addresses via world-accessible devices, bypassing obfuscation mechanisms to read sensitive kernel structures.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-57843?
CVE-2026-57843 is a medium-severity vulnerability in The NetBSD Foundation NetBSD, published on 11 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
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.
Weakness: CWE-732
Which versions are affected by CVE-2026-57843?
How do I fix CVE-2026-57843?
No fix has been published for CVE-2026-57843 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-57843 being exploited?
There is no known exploitation of CVE-2026-57843 in the wild and no public exploit code.
Sources
Also known as GHSA-p59p-jjhh-5885.