CVE-2026-98976 Linux Kernel - Broken Access Control

Linux kernel contains a privilege escalation vulnerability caused by improper lock transfer on propagated mounts in user namespaces, letting user namespace owners unmount locked covers and access restricted files, exploit requires user namespace ownership.

CVSS base score 7.8 /10
High
CISA KEV
Not listed
Public exploit
None known
Authentication
Required
EPSS
0.20% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Broken Access Control
Impact
Privilege Escalation, Information Disclosure
CVSS vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
Published
23 October 2026
Updated
25 October 2026

Vendor fix

Update to the latest Linux kernel version with the fix for mount lock transfer.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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