---
id: CVE-2026-71973
title: >-
  U-Boot before 2026.10-rc4 contains an integer overflow vulnerability in
  sqfs_read_directory_table() function when allocating the directory table
  buffer
summary: >-
  U-Boot before 2026.10-rc4 contains an integer overflow vulnerability in
  sqfs_read_directory_table() function when allocating the directory table
  buffer. Attackers can supply a crafted SquashFS image with an
  attacker-controlled superblock…
severity: medium
cvss: 5.2
cvssVector: 'CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H'
cwe:
  - CWE-190
vendor: u-boot
product: u-boot
affected:
  - u-boot < 2026.10-rc4
published: '2026-09-29'
updated: '2026-09-29'
sourceUpdated: '2026-09-29T22:18:22.080'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-71973'
references:
  - url: 'https://github.com/u-boot/u-boot'
    label: disclosure@vulncheck.com
  - url: 'https://github.com/u-boot/u-boot/blob/v2026.07/fs/squashfs/sqfs.c#L814'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/u-boot/u-boot/commit/561ae28cb56a082cfa90c1c421c4955bc215470b
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/u-boot-before-2026.10-rc4-integer-overflow-in-squashfs-directory-table-allocation
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-29T21:49:08.270Z'
---

## Overview

U-Boot before 2026.10-rc4 contains an integer overflow vulnerability in sqfs_read_directory_table() function when allocating the directory table buffer. Attackers can supply a crafted SquashFS image with an attacker-controlled superblock metablks_count value that causes heap buffer under-allocation and out-of-bounds writes, corrupting heap memory and crashing the bootloader.

## Remediation

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