CVE-2026-31609: smb: client: avoid double-free in smbd_free_send_io() after smbd_send_batch_flush()

Published Apr 24, 2026
·
Updated

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

smb: client: avoid double-free in smbdfreesendio() after smbdsendbatchflush()

smbdsendbatchflush() already calls smbdfreesendio(), so we should not call it again after smbdpostsend() moved it to the batch list.

Affected Software

6 affected componentsFixes available
Linux Linux kernel
Linux Linux kernel<6.18.24
Linux Linux kernel>=6.19<6.19.14
Linux Linux kernel>=7.0<7.0.1
Microsoft azl3 kernel 6.6.130.1-3
Microsoft azl3 kernel 6.6.134.1-2

Event History

Apr 24, 2026
CVE Published
via MITRE·02:42 PM
Data Sourced
via MITRE·02:42 PM
DescriptionSeverity
Data Sourced
via NVD·03:16 PM
RemedyDescriptionSeverityWeaknessAffected Software
Apr 26, 2026
Data Sourced
via Microsoft·08:06 AM
DescriptionSeverityWeaknessAffected Software
Updated
via Microsoft·08:06 AM
DescriptionSeverity
Updated
via Microsoft·08:06 AM
SeverityAffected Software

Frequently Asked Questions

1

What is the severity of CVE-2026-31609?

CVE-2026-31609 is classified as a moderate severity vulnerability due to the potential for a double-free error in the Linux kernel.

2

How do I fix CVE-2026-31609?

To fix CVE-2026-31609, update to a patched version of the Linux kernel that addresses this vulnerability.

3

Which versions of the Linux kernel are affected by CVE-2026-31609?

CVE-2026-31609 affects Linux kernel versions below 6.18.24, between 6.19 and 6.19.14, and between 7.0 and 7.0.1.

4

What component of the Linux kernel is impacted by CVE-2026-31609?

CVE-2026-31609 impacts the SMB client component of the Linux kernel, specifically related to memory management.

5

Are there any known exploits for CVE-2026-31609?

As of now, there are no publicly known exploits specifically targeting CVE-2026-31609.

Contact

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