Always-Incorrect Control Flow Implementation in Linux kernel - CVE-2026-43194
Published: May 7, 2026
Vulnerability identifier: #VU130538
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-43194
CWE-ID: CWE-670
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to improper handling of transmit error return codes in tcp_write_xmit() when processing GSO frames on qdisc-less network devices. A local user can trigger packet drops on a veth-based setup to cause a denial of service.
The issue occurs in configurations using qdisc-less devices, such as veth with TSO disabled and NAPI enabled, where loss of a single segment in a GSO super frame can be treated as loss of the entire frame and leave a TCP connection stuck.
How to mitigate CVE-2026-43194
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/0c9de092ef8c50a7ee9612811566f0aa81d8d7b6
- https://git.kernel.org/stable/c/4cb163e9efcac4cd35c3043e097f25081a5c015c
- https://git.kernel.org/stable/c/56bd32c0edca34041a5c215887fcf562fae2e2db
- https://git.kernel.org/stable/c/7aa767d0d3d04e50ae94e770db7db8197f666970
- https://git.kernel.org/stable/c/9ac6aebef4b4bfc5ed408b0b65645981574bc780
- https://git.kernel.org/stable/c/ae3f627b45fbc3c776a4e484696f3cad7cbb4eca
- https://git.kernel.org/stable/c/c86901d22c89a6bf4e2f013e948aaabc60869893
- https://git.kernel.org/stable/c/ea5d7787635e26ec1194ec7eec0e8e5ae3bd10a5