Use-after-free in Linux kernel - CVE-2026-74727

Vulnerability identifier: #VU144609

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-2026-74727

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to execute arbitrary code.

The vulnerability exists due to a use-after-free in the ovpn peer rehashing logic in drivers/net/ovpn/peer.c when handling concurrent peer update and removal operations. A local user can trigger concurrent peer removal and rehashing to execute arbitrary code.

The issue arises when a removed peer is re-inserted into lookup tables and later freed through RCU while embedded hash entries remain linked.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-ibm (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - update to 7.0.0-42.42
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-ibm (Ubuntu package) - update to 7.0.0-1017.17
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17

• https://git.kernel.org/stable/c/33ec10567fe14456063daf549fdf1a4f53448e4c
• https://git.kernel.org/stable/c/66745480298775f188b2f5ad266643e85a90f73b
• https://git.kernel.org/stable/c/d20c181088984b6eaa8d7fe7cb5ab3510988df59

• Use-after-free in Linux kernel net ovpn driver
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more