Use-after-free in Linux kernel - CVE-2026-90155

Vulnerability identifier: #VU151330

CSH Severity: Medium

CVSS v4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-90155

CWE-ID: CWE-416

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 use-after-free in ksmbd byte-range lock handling when processing SMB byte-range lock requests with blocked dependent waiters. A remote attacker can submit lock requests that leave a dependent waiter attached to a freed lock to cause a denial of service.

Linux kernel
Debian Linux
Ubuntu
linux (Ubuntu package)
linux-realtime (Ubuntu package)
linux-oracle (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-azure (Ubuntu package)
linux-raspi (Ubuntu package)
linux-ibm (Ubuntu package)
linux-azure-fde-7.0 (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-gke (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-aws-7.0 (Ubuntu package)
linux (Debian package)

Install security update from vendor's repository.

linux (Ubuntu package) - update to 7.0.0-43.43
linux-realtime (Ubuntu package) - update to 7.0.0-43.43.1
linux-oracle (Ubuntu package) - update to 7.0.0-1016.18
linux-aws (Ubuntu package) - update to 7.0.0-1017.18
linux-gcp (Ubuntu package) - update to 7.0.0-1017.19
linux-azure (Ubuntu package) - update to 7.0.0-1020.21
linux-raspi (Ubuntu package) - update to 7.0.0-1023.23
linux-ibm (Ubuntu package) - update to 7.0.0-1018.18
linux-azure-fde-7.0 (Ubuntu package) - update to 7.0.0-1019.19~24.04.1
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1017.19~24.04.1
linux-oracle-7.0 (Ubuntu package) - update to 7.0.0-1016.18~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1018.18
linux-gke (Ubuntu package) - update to 7.0.0-1010.11
linux-azure-fde (Ubuntu package) - update to 7.0.0-1019.19
linux-aws-7.0 (Ubuntu package) - update to 7.0.0-1017.18~24.04.1
linux (Debian package) - update to 6.12.115-2

• https://git.kernel.org/stable/c/215e8816b1ac25176d911abb8704390413ccee4b
• https://git.kernel.org/stable/c/514a0b2bc949963497e66cacd433f65dc768a71d

• Use-after-free in Linux kernel smb server
• Debian update for linux
• Ubuntu update for linux, linux-aws, linux-gcp and more
• Ubuntu update for linux-azure
• Ubuntu update for linux-aws-7.0, linux-azure-fde, linux-azure-fde-7.0 and more
• Ubuntu update for linux-raspi