CVE-2026-43390 nstree: tighten permission checks for listing
Privileged services could improperly view other privileged services' namespaces, leading to information leakage between isolated processes.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-43390?
CVE-2026-43390 is a medium-severity vulnerability in Linux kernel, published on 8 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
nstree: tighten permission checks for listing
Even privileged services should not necessarily be able to see other privileged service's namespaces so they can't leak information to each other. Use may_see_all_namespaces() helper that centralizes this policy until the nstree adapts.
Which versions are affected by CVE-2026-43390?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-43390?
Apply the vendor's patch.
Is CVE-2026-43390 being exploited?
There is no known exploitation of CVE-2026-43390 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2026-43390, GHSA-j574-jvxx-m43q, UBUNTU-CVE-2026-43390.