---
id: CVE-2026-31628
title: 'x86/CPU: Fix FPDSS on Zen1'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  x86/CPU: Fix FPDSS on Zen1

  Zen1's hardware divider can leave, under certain circumstances, partial
  results from previous operations.  Those results can be leaked by
  an…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 <
    ed7a3a246309ccc807238f1b4f159ee6d37ff9c4
  - >-
    Linux >= f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 <
    0548529af20e68c6552817834b766646dd3bd7a7
  - >-
    Linux >= f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 <
    1272cfedf4cd1019ddf583917a99b62f2d3645bb
  - >-
    Linux >= f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 <
    91f02726b2203b71545713ecb7fb006e60a2d66f
  - >-
    Linux >= f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 <
    b731aca06387b195058a9f6449a03b62efa1bd10
  - >-
    Linux >= f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 <
    ad17f07e95e6e8505e2153e5b391f0d27eacce25
  - >-
    Linux >= f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 <
    e6af5286efe5a56128b34032572c9ce9ebeccda3
  - >-
    Linux >= f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 <
    546785c719418c6166834a47e372a88f5f7ae893
  - >-
    Linux >= f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 <
    e55d98e7756135f32150b9b8f75d580d0d4b2dd3
  - Linux 5abd1583e06b3963e5c9d915760367de86808b78
  - Linux 4ba461d426490b6ed7e8298c4d3b7a13aa5d2686
  - Linux 5a63725cd18fcee2af6ec46ccb856b64ad3077b4
  - Linux >= 3.16.58 < 3.17
  - Linux >= 4.4.144 < 4.5
  - Linux >= 4.9.102 < 4.10
  - Linux 4.14
published: '2026-04-24'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T08:47:48.248Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-31628'
references:
  - url: 'https://git.kernel.org/stable/c/ed7a3a246309ccc807238f1b4f159ee6d37ff9c4'
  - url: 'https://git.kernel.org/stable/c/0548529af20e68c6552817834b766646dd3bd7a7'
  - url: 'https://git.kernel.org/stable/c/1272cfedf4cd1019ddf583917a99b62f2d3645bb'
  - url: 'https://git.kernel.org/stable/c/91f02726b2203b71545713ecb7fb006e60a2d66f'
  - url: 'https://git.kernel.org/stable/c/b731aca06387b195058a9f6449a03b62efa1bd10'
  - url: 'https://git.kernel.org/stable/c/ad17f07e95e6e8505e2153e5b391f0d27eacce25'
  - url: 'https://git.kernel.org/stable/c/e6af5286efe5a56128b34032572c9ce9ebeccda3'
  - url: 'https://git.kernel.org/stable/c/546785c719418c6166834a47e372a88f5f7ae893'
  - url: 'https://git.kernel.org/stable/c/e55d98e7756135f32150b9b8f75d580d0d4b2dd3'
tags:
  - cve.org
epss: 0.00171
epssPercentile: 0.05677
ingestedAt: '2026-09-08T15:33:26.990Z'
---

## Overview

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

x86/CPU: Fix FPDSS on Zen1

Zen1's hardware divider can leave, under certain circumstances, partial
results from previous operations.  Those results can be leaked by
another, attacker thread.

Fix that with a chicken bit.

## Affected

- `Linux >= f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 < ed7a3a246309ccc807238f1b4f159ee6d37ff9c4`
- `Linux >= f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 < 0548529af20e68c6552817834b766646dd3bd7a7`
- `Linux >= f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 < 1272cfedf4cd1019ddf583917a99b62f2d3645bb`
- `Linux >= f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 < 91f02726b2203b71545713ecb7fb006e60a2d66f`
- `Linux >= f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 < b731aca06387b195058a9f6449a03b62efa1bd10`
- `Linux >= f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 < ad17f07e95e6e8505e2153e5b391f0d27eacce25`
- `Linux >= f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 < e6af5286efe5a56128b34032572c9ce9ebeccda3`
- `Linux >= f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 < 546785c719418c6166834a47e372a88f5f7ae893`
- `Linux >= f7f3dc00f61261cdc9ccd8b886f21bc4dffd6fd9 < e55d98e7756135f32150b9b8f75d580d0d4b2dd3`
- `Linux 5abd1583e06b3963e5c9d915760367de86808b78`
- `Linux 4ba461d426490b6ed7e8298c4d3b7a13aa5d2686`
- `Linux 5a63725cd18fcee2af6ec46ccb856b64ad3077b4`
- `Linux >= 3.16.58 < 3.17`
- `Linux >= 4.4.144 < 4.5`
- `Linux >= 4.9.102 < 4.10`
- `Linux 4.14`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.