Executive brief
A vulnerability in the Linux kernel's namespace management could allow privileged services to see information about other privileged services that they should not have access to. This flaw breaks the isolation between different system components, potentially leading to information leaks between sensitive services. The issue has been addressed by tightening the permission checks required to list system namespaces.
Technical details
A vulnerability was identified in the nstree component of the Linux kernel where permission checks for listing namespaces were insufficient. Specifically, the listns() function allowed privileged services to view namespaces belonging to other privileged services, violating the principle of least privilege and isolation. The fix involves implementing the may_see_all_namespaces() helper to centralize and tighten the visibility policy within kernel/nstree.c. This ensures that even services with high privileges cannot automatically inspect the namespaces of other high-privilege entities unless explicitly permitted.
Affected products
- Linux Linux Kernel 6.19 to 6.19.9, 7.0-rc1, 7.0-rc2
Timeline
- 2026-05-08: disclosed
- 2026-05-08: advisory
- 2026-03-19: patched: Patch committed to stable tree