SB20260720192 - Use-after-free in Linux kernel net ovpn driver

Description

This security bulletin contains information about 1 vulnerability.

1) Use-after-free (CVE-ID: CVE-2026-64044)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to a use-after-free in ovpn_nl_peer_new_doit() and the ovpn peer reference handling when processing peer creation error paths for TCP peers. A local user can trigger concurrent socket activity during peer creation failure handling to cause a denial of service.

The issue affects the TCP path, where the peer may remain reachable through sk_user_data before detachment, and exploitation depends on concurrent in-flight userspace or strparser-driven access to the peer.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/0c3ef71879c0264de6c42463031d9e057da87840
• https://git.kernel.org/stable/c/1fef6614673ff0846d30acdeeaf3cf98bb5f6116
• https://git.kernel.org/stable/c/8298834912d76dbc82c12b6b4ab7590ed2bb8ae5