Missing Authorization in Linux kernel - CVE-2026-99281
Published: November 8, 2026
Vulnerability identifier: #VU161900
CSH Severity: Low
CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-99281
CWE-ID: CWE-862
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to gain unauthorized access to TUN/TAP network devices.
The vulnerability exists due to a missing capability check in the Linux kernel TUN/TAP device attachment logic when neither an owner nor a group is assigned to a device. A local user can open an accessible /dev/net/tun device node and attach to an existing ownerless and groupless device without CAP_NET_ADMIN to gain unauthorized access to its packet interface.
Affected software
Linux kernel
How to mitigate CVE-2026-99281
Install security update from vendor's repository.