---
title: "CVE-2026-89487: Linux Kernel openvswitch - Broken Access Control"
description: "Linux kernel openvswitch contains a broken access control vulnerability caused by improper handling of skb_tx_error() on packets still in use, letting unprivileged attackers perform unauthorized page-cache writes, exploit requires triggering specific packet flows with MSG_ZEROCOPY skb."
url: https://panop.io/threat-heartbeat/CVE-2026-89487/
---

# CVE-2026-89487 Linux Kernel openvswitch - Broken Access Control

Linux kernel openvswitch contains a broken access control vulnerability caused by improper handling of skb\_tx\_error() on packets still in use, letting unprivileged attackers perform unauthorized page-cache writes, exploit requires triggering specific packet flows with MSG\_ZEROCOPY skb.

CVSS base score 7.8 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Required

EPSS

0.13% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-89487)

## Details

Type

Broken Access Control

Impact

Privilege Escalation, Data Tampering

CVSS vector

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

Published

11 September 2026

Updated

15 October 2026

## Vendor fix

Update to the latest Linux kernel version containing the fix that moves skb\_tx\_error() to the flow-miss drop 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-2026-89487](https://nvd.nist.gov/vuln/detail/CVE-2026-89487)
- [https://git.kernel.org/stable/c/0dbc2398fca3bb33eda963849f865ddb1b3aa05e](https://git.kernel.org/stable/c/0dbc2398fca3bb33eda963849f865ddb1b3aa05e)
- [https://git.kernel.org/stable/c/5d85eef222cfd28e73deed7402c100229e8b9e6e](https://git.kernel.org/stable/c/5d85eef222cfd28e73deed7402c100229e8b9e6e)
- [https://git.kernel.org/stable/c/6767d70cf46f65807a6a4c4406a518e6c12e36ae](https://git.kernel.org/stable/c/6767d70cf46f65807a6a4c4406a518e6c12e36ae)
- [https://git.kernel.org/stable/c/e41a59fc056f63a7a1f42788913c53cc48d744aa](https://git.kernel.org/stable/c/e41a59fc056f63a7a1f42788913c53cc48d744aa)
- [https://git.kernel.org/stable/c/4477222e2916a18e273edc139c955ade6bbb7a69](https://git.kernel.org/stable/c/4477222e2916a18e273edc139c955ade6bbb7a69)
- [https://git.kernel.org/stable/c/48db11e115d1b232edc5591604adc6eda95cd545](https://git.kernel.org/stable/c/48db11e115d1b232edc5591604adc6eda95cd545)
- [https://git.kernel.org/stable/c/4d5c460ef8754be1d43b16dbf02695b008b207d6](https://git.kernel.org/stable/c/4d5c460ef8754be1d43b16dbf02695b008b207d6)
- [https://git.kernel.org/stable/c/5de5d554141a15b3f1f5c978fd9f7f4fd6d0600a](https://git.kernel.org/stable/c/5de5d554141a15b3f1f5c978fd9f7f4fd6d0600a)

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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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