Memory leak in Linux kernel - CVE-2026-90169

Vulnerability identifier: #VU151313

CSH Severity: Medium

CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-90169

CWE-ID: CWE-401

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to a memory leak in ksmbd preauthentication session handling when a client disconnects after sending a binding NTLM negotiate request and before sending an authenticate request. A remote attacker can initiate an SMB3.1.1 multichannel binding negotiation and disconnect before authentication completes to cause a denial of service.

Linux kernel
Debian Linux
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)
linux (Debian package)

Install security update from vendor's repository.

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
linux (Debian package) - update to 6.12.111-1

• https://git.kernel.org/stable/c/06c7b1d731bc105a8644f1b70165ba8b9416cbab
• https://git.kernel.org/stable/c/8e2ebc77678832e981adc008d25cd8f67d08ebc4
• https://git.kernel.org/stable/c/a41a98ee16ae038751b6639decadaa3ce15ca18a
• https://git.kernel.org/stable/c/b62b1ebb25f0a19067ed5b1a86036b2dc98be44f
• https://git.kernel.org/stable/c/effcf48d79d8aa53113d8289e140746f25ceb62c

• Memory leak in Linux kernel smb server
• Debian update for linux
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more