CVE-2026-43403: nsfs: tighten permission checks for ns iteration ioctls

Published May 8, 2026
·
Updated

In the Linux kernel, the following vulnerability has been resolved:

nsfs: tighten permission checks for ns iteration ioctls

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

6 affected components
Linux Linux kernel
Linux Linux kernel>=6.12<6.12.78
Linux Linux kernel>=6.13<6.18.20
Linux Linux kernel>=6.19<6.19.9
Linux Linux kernel=7.0-rc1
Linux Linux kernel=7.0-rc2

Event History

May 8, 2026
CVE Published
via MITRE·02:21 PM
Data Sourced
via MITRE·02:21 PM
DescriptionSeverity
Data Sourced
via NVD·03:16 PM
RemedyDescriptionSeverityAffected Software

Frequently Asked Questions

1

What is the severity of CVE-2026-43403?

The severity of CVE-2026-43403 is rated as high with a score of 8.8.

2

What systems are affected by CVE-2026-43403?

CVE-2026-43403 affects the Linux kernel.

3

How do I fix CVE-2026-43403?

To fix CVE-2026-43403, you should update your Linux kernel to the latest version that addresses this vulnerability.

4

What type of vulnerability is CVE-2026-43403?

CVE-2026-43403 is related to improper permission checks in the Linux kernel affecting namespace iteration ioctls.

5

What are the implications of CVE-2026-43403?

The implications of CVE-2026-43403 include potential information leaks between privileged services on the Linux platform.

Contact

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