---
id: CVE-2026-80580
title: 'fbdev: bound mode sysfs output to the sysfs buffer'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  fbdev: bound mode sysfs output to the sysfs buffer

  mode_string() uses snprintf() which can return a value larger than the
  remaining buffer space. show_modes() accumula…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    873a1aa15c313263f2e18b38cf525623cc4fabf6
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    d15d51fb26e830af58f3f21964f1c09c239077ea
  - Linux 2.6.12
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T19:17:49.806822Z'
published: '2026-08-26'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T19:26:28.187Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-80580'
references:
  - url: 'https://git.kernel.org/stable/c/873a1aa15c313263f2e18b38cf525623cc4fabf6'
  - url: 'https://git.kernel.org/stable/c/d15d51fb26e830af58f3f21964f1c09c239077ea'
tags:
  - cve.org
epss: 0.00112
epssPercentile: 0.01298
ingestedAt: '2026-10-16T19:46:24.315Z'
---

## Overview

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

fbdev: bound mode sysfs output to the sysfs buffer

mode_string() uses snprintf() which can return a value larger than the
remaining buffer space. show_modes() accumulates the return value into i
without checking whether i has reached PAGE_SIZE, causing the offset to
advance past the sysfs buffer if the modelist is long enough.

Add a size parameter to mode_string() and use scnprintf() to return
only the bytes actually written. Add an early return when offset
already exceeds the buffer. In show_modes(), stop accumulating once
the buffer is full.

## Affected

- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 873a1aa15c313263f2e18b38cf525623cc4fabf6`
- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < d15d51fb26e830af58f3f21964f1c09c239077ea`
- `Linux 2.6.12`

## Remediation

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