CVE-2026-98990
kernel: namespace: check a submount for references right before unmounting it
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · October 23, 2026
Updated · October 30, 2026
Description
A flaw was found in the Linux kernel. A local user can trigger a Denial of Service (DoS) or unexpected system behavior by unmounting filesystem submounts that are still actively in use. During the removal of propagating mount trees, the kernel fails to verify that a submount is free of active references immediately before detaching it. Consequently, an in-use mount can be prematurely removed, leaving processes in an invalid state and disrupting filesystem operations.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 4.1CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H
CWE-826 · Premature Release of Resource During Expected Lifetime