CVE-2026-43378: smb: server: fix use-after-free in smb2_open()

Published May 8, 2026
·
Updated

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

smb: server: fix use-after-free in smb2open()

The opinfo pointer obtained via rcudereference(fp->fopinfo) is dereferenced after rcureadunlock(), creating a use-after-free window.

Affected Software

9 affected components
Linux Linux kernel
Linux Linux kernel>=5.15<6.1.167
Linux Linux kernel>=6.2<6.6.130
Linux Linux kernel>=6.7<6.12.78
Linux Linux kernel>=6.13<6.18.19
Linux Linux kernel>=6.19<6.19.9
Linux Linux kernel=7.0-rc1
Linux Linux kernel=7.0-rc2
Linux Linux kernel=7.0-rc3

Event History

May 8, 2026
CVE Published
via MITRE·02:21 PM
Data Sourced
via MITRE·02:21 PM
DescriptionSeverity
Data Sourced
via NVD·03:16 PM
RemedyDescriptionSeverityWeaknessAffected Software

Frequently Asked Questions

1

What level of access does an attacker need?

The CVSS vector indicates the issue is exploitable over the network with low attack complexity. It requires no privileges and no user interaction.

2

What is the potential impact of successful exploitation?

The vulnerability is rated critical with high confidentiality, integrity, and availability impact in the provided CVSS vector. It could therefore affect data confidentiality, system integrity, and service availability.

3

What systems should be prioritized for remediation?

Prioritize Linux systems running the Linux kernel SMB server functionality, particularly those reachable by untrusted network clients. The supplied data does not identify affected or fixed kernel version numbers.

4

What should be done if the system cannot be patched immediately?

The available data supports reducing exposure by limiting untrusted network access to the SMB server, since exploitation is network-based and does not require authentication. Apply the fixes referenced by the supplied stable kernel commits when possible.

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