CVE-2026-31678 Linux — Exploit & Vulnerability Details HIGH

Parameter	Value
CVSS	7.8 (HIGH)
Affected Versions	4.3 — 7.0
Fixed In	6.1.168
Type	CWE-367 (Time-of-check Time-of-use (TOCTOU))
Vendor	Linux
Public PoC	No

In the Linux kernel, the following vulnerability has been resolved: openvswitch: defer tunnel netdev_put to RCU release ovs_netdev_tunnel_destroy() may run after NETDEV_UNREGISTER already detached the device. Dropping the netdev reference in destroy can race with concurrent readers that still observe vport->dev. Do not release vport->dev in ovs_netdev_tunnel_destroy().

Instead, let vport_netdev_free() drop the reference from the RCU callback, matching the non-tunnel destroy path and avoiding additional synchronization under RTNL.

Attack Parameters

Attack Vector

Local

Requires local access

Attack Complexity

Low

Easy to exploit

Privileges Required

Low

Basic privileges needed

User Interaction

None

No user interaction needed

Impact Assessment

Confidentiality

High

Complete data leak

Integrity

High

Complete data modification

Availability

High

Complete denial of service

CVSS Vector v3.1

Weakness Type (CWE)

CWE-367 Time-of-check Time-of-use (TOCTOU)

Vulnerable Products 11

Configuration	From (including)	Up to (excluding)
Linux Linux_Kernel cpe:2.3:o:linux:linux_kernel::::::::	`4.3`	`6.1.168`
Linux Linux_Kernel cpe:2.3:o:linux:linux_kernel::::::::	`4.3`	`6.6.131`
Linux Linux_Kernel cpe:2.3:o:linux:linux_kernel::::::::	`4.3`	`6.12.80`
Linux Linux_Kernel cpe:2.3:o:linux:linux_kernel::::::::	`4.3`	`6.18.21`
Linux Linux_Kernel cpe:2.3:o:linux:linux_kernel::::::::	`4.3`	`6.19.11`
Linux Linux_Kernel cpe:2.3:o:linux:linux_kernel::::::::	`4.3`	`7.0`
Linux Linux_Kernel cpe:2.3:o:linux:linux_kernel:7.0:rc1::::::	—	—
Linux Linux_Kernel cpe:2.3:o:linux:linux_kernel:7.0:rc2::::::	—	—
Linux Linux_Kernel cpe:2.3:o:linux:linux_kernel:7.0:rc3::::::	—	—
Linux Linux_Kernel cpe:2.3:o:linux:linux_kernel:7.0:rc4::::::	—	—
Linux Linux_Kernel cpe:2.3:o:linux:linux_kernel:7.0:rc5::::::	—	—