Use-after-free in Linux kernel - CVE-2026-23427

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Main Vulnerability Database Vulnerabilities #VU124944

Use-after-free in Linux kernel - CVE-2026-23427

Published: April 6, 2026


Vulnerability identifier: #VU124944
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-23427
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

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

The vulnerability exists due to use-after-free in parse_durable_handle_context() when handling a DURABLE_REQ_V2 context with SMB2_FLAGS_REPLAY_OPERATION. A remote attacker can send a specially crafted replay request to cause a denial of service.

The issue occurs during durable v2 replay of active file handles because an active file handle connection pointer can be overwritten and later dereferenced after the overwriting connection is freed.


Affected software

Linux kernel
Debian Linux
Ubuntu
linux (Debian package)
linux (Ubuntu package)
linux-hwe-6.17 (Ubuntu package)
linux-azure-fde-6.17 (Ubuntu package)
linux-raspi (Ubuntu package)
linux-azure-6.17 (Ubuntu package)
linux-nvidia-6.17 (Ubuntu package)
linux-oem-6.17 (Ubuntu package)

How to mitigate CVE-2026-23427

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Debian package) - update to 6.12.85-1
linux (Ubuntu package) - update to 6.17.0-40.40
linux-hwe-6.17 (Ubuntu package) - update to 6.17.0-40.40~24.04.1
linux-azure-fde-6.17 (Ubuntu package) - update to 6.17.0-1018.18~24.04.1
linux-raspi (Ubuntu package) - update to 6.17.0-1021.21
linux-azure-6.17 (Ubuntu package) - update to 6.17.0-1021.21~24.04.1
linux-nvidia-6.17 (Ubuntu package) - update to 6.17.0-1026.26
linux-oem-6.17 (Ubuntu package) - update to 6.17.0-1028.28

External References

Related Security Bulletins