CVE intelligence

CVE-2026-43378

Vulnerability intelligence

Published May 8, 2026Sources checked Oct 27, 2026

7.8HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2026-43378 and is rated High severity with a CVSS score of 7.8. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Ubuntu Security Notices guidance

Vendor revision: Sep 22, 2026

Vendor remediation details

This update corrects flaws in the following subsystems: - x86 architecture; - InfiniBand drivers; - Network drivers; - NVME drivers; - Ext4 file system; - SMB network file system; - IPv4 networking; - Network traffic control; - TCP network protocol; - Locking primitives; - IPv6 networking; - Multipath TCP; - Netfilter; - Open vSwitch; - SCTP protocol; - SMC sockets; (CVE-2026-31414, CVE-2026-31448, CVE-2026-31705, CVE-2026-43198, CVE-2026-43378, CVE-2026-43499, CVE-2026-46266, CVE-2026-46331, CVE-2026-52924, CVE-2026-52989, CVE-2026-53086, CVE-2026-53176, CVE-2026-53212, CVE-2026-53215, CVE-2026-53224, CVE-2026-53225, CVE-2026-53228, CVE-2026-53246, CVE-2026-53359, CVE-2026-64531)

Ubuntu Security Notices guidance

Vendor revision: Sep 2, 2026

Vendor remediation details

Ubuntu Security Notices guidance

Vendor revision: Aug 27, 2026

Vendor remediation details

CISA KEVNot listedBased on the latest collected catalog

EPSS0.3%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-43378?

In the Linux kernel, the following vulnerability has been resolved:

smb: server: fix use-after-free in smb2_open()

The opinfo pointer obtained via rcu_dereference(fp->f_opinfo) is dereferenced after rcu_read_unlock(), creating a use-after-free window.

Source: NVD