---
title: "CVE-2026-89788: Linux Kernel - Use After Free"
description: "Linux kernel contains a use-after-free vulnerability in ksmbd's smb2_tree_connect() caused by improper reference handling during tree connection initialization, letting attackers cause memory corruption, exploit requires concurrent session logoff race condition."
url: https://panop.io/threat-heartbeat/CVE-2026-89788/
---

# CVE-2026-89788 Linux Kernel - Use After Free

Linux kernel contains a use-after-free vulnerability in ksmbd's smb2\_tree\_connect() caused by improper reference handling during tree connection initialization, letting attackers cause memory corruption, exploit requires concurrent session logoff race condition.

CVSS base score 9.8 /10

Critical

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.55% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-89788)

## Details

Type

Use After Free

Impact

Denial Of Service, Remote Code Execution

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Published

16 September 2026

Updated

15 October 2026

## Vendor fix

Update to the latest Linux kernel version containing the fix for ksmbd use-after-free in smb2\_tree\_connect.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-89788](https://nvd.nist.gov/vuln/detail/CVE-2026-89788)
- [https://git.kernel.org/stable/c/4e30fbd26e84efa2e5cbec4eb11e126ac0c79313](https://git.kernel.org/stable/c/4e30fbd26e84efa2e5cbec4eb11e126ac0c79313)
- [https://git.kernel.org/stable/c/b5ec6c462aab1062cf5d1e667ba7c6442f737055](https://git.kernel.org/stable/c/b5ec6c462aab1062cf5d1e667ba7c6442f737055)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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