---
id: CVE-2026-110600
title: >-
  xlsxio through 0.2.37 contains a NULL pointer dereference vulnerability in
  main_sheet_get_sheetfile_expat_callback_element_start() in lib/xlsxio_read.c
  that allows attackers to crash applications via crafted files
summary: >-
  xlsxio through 0.2.37 contains a NULL pointer dereference vulnerability in
  main_sheet_get_sheetfile_expat_callback_element_start() in lib/xlsxio_read.c
  that allows attackers to crash applications via crafted files. Attackers can
  supply a…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'
cwe:
  - CWE-476
published: '2026-10-14'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T15:17:11.387'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-110600'
references:
  - url: >-
      https://github.com/brechtsanders/xlsxio/blob/0.2.37/lib/xlsxio_read.c#L851-L866
    label: disclosure@vulncheck.com
  - url: 'https://github.com/brechtsanders/xlsxio/issues/151'
    label: disclosure@vulncheck.com
  - url: 'https://hackmd.io/@haind-pwn/xlsxio-relationship-missing-id-null-deref'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/xlsxio-through-0.2.37-null-pointer-dereference-via-worksheet-relationship-without-id
    label: disclosure@vulncheck.com
tags:
  - nvd
ingestedAt: '2026-10-14T15:36:14.002Z'
---

## Overview

xlsxio through 0.2.37 contains a NULL pointer dereference vulnerability in main_sheet_get_sheetfile_expat_callback_element_start() in lib/xlsxio_read.c that allows attackers to crash applications via crafted files. Attackers can supply a .xlsx file whose workbook.xml.rels contains a worksheet Relationship lacking an Id attribute, crashing the process when xlsxioread_sheet_open() is called.

## Remediation

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