---
title: "CVE-2026-89789: Linux Kernel - Use After Free"
description: "Linux kernel contains a use-after-free vulnerability in gtp_newlink() caused by freeing tid_hash and addr_hash without waiting for RCU grace period, letting attackers cause memory corruption via concurrent gtp_encap_recv(), exploit requires triggering error path."
url: https://panop.io/threat-heartbeat/CVE-2026-89789/
---

# CVE-2026-89789 Linux Kernel - Use After Free

Linux kernel contains a use-after-free vulnerability in gtp\_newlink() caused by freeing tid\_hash and addr\_hash without waiting for RCU grace period, letting attackers cause memory corruption via concurrent gtp\_encap\_recv(), exploit requires triggering error path.

CVSS base score 7.8 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Required

EPSS

0.16% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-89789)

## Details

Type

Use After Free

Impact

Remote Code Execution, Denial Of Service

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/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 with the fix that adds synchronize\_net() in gtp\_newlink() error path.

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-2026-89789](https://nvd.nist.gov/vuln/detail/CVE-2026-89789)
- [https://git.kernel.org/stable/c/7677eb2cbf2cc7446de474c01a6b06277c0051e5](https://git.kernel.org/stable/c/7677eb2cbf2cc7446de474c01a6b06277c0051e5)
- [https://git.kernel.org/stable/c/8d85498016a5bb56339734a14c276209fa65bafc](https://git.kernel.org/stable/c/8d85498016a5bb56339734a14c276209fa65bafc)
- [https://git.kernel.org/stable/c/d989e22ae9802c52c56ad4284d0caf26696cf6ae](https://git.kernel.org/stable/c/d989e22ae9802c52c56ad4284d0caf26696cf6ae)
- [https://git.kernel.org/stable/c/e3b9aa0773abd5d4ed90be41ce5306c146d5b09e](https://git.kernel.org/stable/c/e3b9aa0773abd5d4ed90be41ce5306c146d5b09e)
- [https://git.kernel.org/stable/c/fcafb2b1430824bae4258c01a439ec97ca0c6973](https://git.kernel.org/stable/c/fcafb2b1430824bae4258c01a439ec97ca0c6973)
- [https://git.kernel.org/stable/c/fd8396cfecbd904468c71362f08aaa25f96d5337](https://git.kernel.org/stable/c/fd8396cfecbd904468c71362f08aaa25f96d5337)
- [https://git.kernel.org/stable/c/3ca3da5c305caa873ddb81e8c6b118143f6dd3d1](https://git.kernel.org/stable/c/3ca3da5c305caa873ddb81e8c6b118143f6dd3d1)
- [https://git.kernel.org/stable/c/6f815c2fb6ab20385f81c353cdad0ea3b88132af](https://git.kernel.org/stable/c/6f815c2fb6ab20385f81c353cdad0ea3b88132af)

[← All CVEs](https://panop.io/threat-heartbeat/)

## 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

Panop answers these inside your environment, for this CVE and every other finding.

[Book a demo](https://panop.io/demo)