---
title: "CVE-2026-89459: Linux kernel - Denial of Service"
description: "Linux kernel s390/percpu contains an assembler macro argument parsing issue caused by improper whitespace handling in MVIY_PERCPU() macro, letting the assembler fail to emit necessary instructions, potentially causing exception return path failures, exploit requires use of older binutils versions."
url: https://panop.io/threat-heartbeat/CVE-2026-89459/
---

# CVE-2026-89459 Linux kernel - Denial of Service

Linux kernel s390/percpu contains an assembler macro argument parsing issue caused by improper whitespace handling in MVIY\_PERCPU() macro, letting the assembler fail to emit necessary instructions, potentially causing exception return path failures, exploit requires use of older binutils versions.

CVSS base score 7.0 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Required

EPSS

0.14% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-89459)

## Details

Type

Denial of Service

Impact

Denial Of Service

CVSS vector

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

Published

11 September 2026

Updated

15 October 2026

## Vendor fix

Update binutils to version 2.39 or later, or apply the Linux kernel patch fixing MVIY\_PERCPU() macro usage.

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-2026-89459](https://nvd.nist.gov/vuln/detail/CVE-2026-89459)
- [https://git.kernel.org/stable/c/91770b08a120967077ae78600612f18bc5ee3caf](https://git.kernel.org/stable/c/91770b08a120967077ae78600612f18bc5ee3caf)
- [https://git.kernel.org/stable/c/101782f8945a125044347312d74d488c05741c4a](https://git.kernel.org/stable/c/101782f8945a125044347312d74d488c05741c4a)

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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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