CVE-2026-43391: nsfs: tighten permission checks for handle opening
In the Linux kernel, the following vulnerability has been resolved:
nsfs: tighten permission checks for handle opening
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 mayseeallnamespaces() helper that centralizes this policy until the nstree adapts.
Affected Software
Event History
Frequently Asked Questions
Who is most likely to be exposed to this issue?
Systems running the Linux kernel where privileged services can access namespace handles for other privileged services are the relevant exposure scenario. The issue concerns unintended visibility between privileged services' namespaces.
What level of access does an attacker need?
The supplied vector indicates local access, low attack complexity, and low privileges are required. No user interaction is required.
What is the potential impact if exploitation succeeds?
The vulnerability can allow information disclosure, modification, and denial of service with high impact. Its scope is changed, meaning the security impact can extend beyond the initially authorized security context.