Heap-based buffer overflow in Linux kernel - CVE-2026-43185
Published: May 7, 2026
Vulnerability identifier: #VU130545
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber
CVE-ID: CVE-2026-43185
CWE-ID: CWE-122
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a remote attacker to execute arbitrary code.
The vulnerability exists due to a heap-based buffer overflow in smb_direct_prepare_negotiation() when processing crafted SMB Direct negotiation messages. A remote attacker can send a crafted preferred_send_size value followed by a large second message to execute arbitrary code.
The issue is triggered by a signedness error that causes a malicious preferred_send_size value of 0x80000000 to be treated as smaller than max_recv_size and used to set the allowed receive size for the next message.
How to mitigate CVE-2026-43185
Install security update from vendor's repository.