CVE intelligence

CVE-2026-43379

Vulnerability intelligence

Published May 8, 2026Sources checked Oct 28, 2026

9.8CRITICALCVSS out of 10

What this means

Review the available evidence

CVE-2026-43379 and is rated Critical severity with a CVSS score of 9.8. 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: Aug 18, 2026

Vendor remediation details

This update corrects flaws in the following subsystems: - x86 architecture; - InfiniBand drivers; - Media drivers; - Network drivers; - Mellanox network drivers; - Texas Instruments network drivers; - NVME drivers; - File systems infrastructure; - SMB network file system; - IPv4 networking; - Network traffic control; - TCP network protocol; - Locking primitives; - Memory management; - IPv6 networking; - Multipath TCP; - Netfilter; - RxRPC session sockets; - SCTP protocol; - SMC sockets; (CVE-2026-31405, CVE-2026-31414, CVE-2026-31501, CVE-2026-31589, CVE-2026-31633, CVE-2026-31636, CVE-2026-31705, CVE-2026-43198, CVE-2026-43379, CVE-2026-43465, CVE-2026-43499, CVE-2026-46113, CVE-2026-46137, CVE-2026-46242, CVE-2026-46331, CVE-2026-52924, CVE-2026-52989, CVE-2026-53086, CVE-2026-53131, CVE

CISA KEVNot listedBased on the latest collected catalog

EPSS0.4%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-43379?

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

ksmbd: fix use-after-free in smb_lazy_parent_lease_break_close()

opinfo pointer obtained via rcu_dereference(fp->f_opinfo) is being accessed after rcu_read_unlock() has been called. This creates a race condition where the memory could be freed by a concurrent writer between the unlock and the subsequent pointer dereferences (opinfo->is_lease, etc.), leading to a use-after-free.

Source: NVD