---
id: CVE-2018-14404
title: >-
  A NULL pointer dereference vulnerability exists in the
  xpath.c:xmlXPathCompOpEval() function of libxml2 through 2.9.8 when parsing an
  invalid XPath expression in the XPATH_OP_AND or XPATH_OP_OR case
summary: >-
  A NULL pointer dereference vulnerability exists in the
  xpath.c:xmlXPathCompOpEval() function of libxml2 through 2.9.8 when parsing an
  invalid XPath expression in the XPATH_OP_AND or XPATH_OP_OR case. Applications
  processing untrusted XSL…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'
cwe:
  - CWE-476
  - CWE-476
vendor: xmlsoft
product: libxml2
affected:
  - ubuntu_linux = 12.04
  - ubuntu_linux = 14.04
  - ubuntu_linux = 16.04
  - ubuntu_linux = 18.04
  - debian_linux
  - libxml2 <= 2.9.8
published: '2018-07-19'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T07:16:42.140'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2018-14404'
references:
  - url: 'https://access.redhat.com/errata/RHSA-2019:1543'
    label: cve@mitre.org
  - url: 'https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=901817'
    label: cve@mitre.org
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=1595985'
    label: cve@mitre.org
  - url: 'https://gitlab.gnome.org/GNOME/libxml2/issues/10'
    label: cve@mitre.org
  - url: 'https://lists.debian.org/debian-lts-announce/2018/09/msg00035.html'
    label: cve@mitre.org
  - url: 'https://lists.debian.org/debian-lts-announce/2020/09/msg00009.html'
    label: cve@mitre.org
  - url: 'https://security.netapp.com/advisory/ntap-20190719-0002/'
    label: cve@mitre.org
  - url: 'https://usn.ubuntu.com/3739-1/'
    label: cve@mitre.org
  - url: 'https://usn.ubuntu.com/3739-2/'
    label: cve@mitre.org
  - url: 'https://access.redhat.com/errata/RHSA-2019:1543'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=901817'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=1595985'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://gitlab.gnome.org/GNOME/libxml2/issues/10'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://lists.debian.org/debian-lts-announce/2018/09/msg00035.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://lists.debian.org/debian-lts-announce/2020/09/msg00009.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://security.netapp.com/advisory/ntap-20190719-0002/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://usn.ubuntu.com/3739-1/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://usn.ubuntu.com/3739-2/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-398330.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
epss: 0.0365
epssPercentile: 0.89355
ingestedAt: '2026-10-14T07:21:04.802Z'
---

## Overview

A NULL pointer dereference vulnerability exists in the xpath.c:xmlXPathCompOpEval() function of libxml2 through 2.9.8 when parsing an invalid XPath expression in the XPATH_OP_AND or XPATH_OP_OR case. Applications processing untrusted XSL format inputs with the use of the libxml2 library may be vulnerable to a denial of service attack due to a crash of the application.

## Affected

- `ubuntu_linux = 12.04`
- `ubuntu_linux = 14.04`
- `ubuntu_linux = 16.04`
- `ubuntu_linux = 18.04`
- `debian_linux`
- `libxml2 <= 2.9.8`

## Remediation

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