---
id: CVE-2021-3517
title: >-
  There is a flaw in the xml entity encoding functionality of libxml2 in
  versions before 2.9.11
summary: >-
  There is a flaw in the xml entity encoding functionality of libxml2 in
  versions before 2.9.11. An attacker who is able to supply a crafted file to be
  processed by an application linked with the affected functionality of libxml2
  could tri…
severity: high
cvss: 8.6
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H'
cwe:
  - CWE-787
  - CWE-787
  - CWE-125
vendor: xmlsoft
product: libxml2
affected:
  - libxml2 < 2.9.11
  - jboss_core_services
  - enterprise_linux = 8.0
  - fedora = 33
  - fedora = 34
  - debian_linux = 9.0
  - active_iq_unified_manager
  - clustered_data_ontap
  - clustered_data_ontap_antivirus_connector
  - 'e-series_santricity_os_controller >= 11.0.0, <= 11.70.1'
  - e-series_santricity_storage_manager
  - e-series_santricity_web_services
  - hci_management_node
  - manageability_software_development_kit
  - oncommand_insight
  - oncommand_workflow_automation
  - ontap_select_deploy_administration_utility
  - santricity_unified_manager
  - snapdrive
  - snapmanager
  - solidfire
  - hci_h410c_firmware
  - >-
    communications_cloud_native_core_network_function_cloud_native_environment =
    1.10.0
  - enterprise_manager_base_platform = 13.4.0.0
  - enterprise_manager_base_platform = 13.5.0.0
  - mysql_workbench <= 8.0.26
  - openjdk = 8
  - peoplesoft_enterprise_peopletools = 8.58
  - real_user_experience_insight = 13.4.1.0
  - real_user_experience_insight = 13.5.1.0
  - zfs_storage_appliance_kit = 8.8
patched:
  - libxml2 2.9.11
published: '2021-05-19'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T10:17:43.473'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-3517'
references:
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=1954232'
    label: secalert@redhat.com
  - url: >-
      https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E
    label: secalert@redhat.com
  - url: >-
      https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E
    label: secalert@redhat.com
  - url: 'https://lists.debian.org/debian-lts-announce/2021/05/msg00008.html'
    label: secalert@redhat.com
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BZOMV5J4PMZAORVT64BKLV6YIZAFDGX6/
    label: secalert@redhat.com
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QVM4UJ3376I6ZVOYMHBNX4GY3NIV52WV/
    label: secalert@redhat.com
  - url: 'https://security.gentoo.org/glsa/202107-05'
    label: secalert@redhat.com
  - url: 'https://security.netapp.com/advisory/ntap-20210625-0002/'
    label: secalert@redhat.com
  - url: 'https://security.netapp.com/advisory/ntap-20211022-0004/'
    label: secalert@redhat.com
  - url: 'https://www.oracle.com/security-alerts/cpuapr2022.html'
    label: secalert@redhat.com
  - url: 'https://www.oracle.com/security-alerts/cpujan2022.html'
    label: secalert@redhat.com
  - url: 'https://www.oracle.com/security-alerts/cpujul2022.html'
    label: secalert@redhat.com
  - url: 'https://www.oracle.com/security-alerts/cpuoct2021.html'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=1954232'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://lists.debian.org/debian-lts-announce/2021/05/msg00008.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BZOMV5J4PMZAORVT64BKLV6YIZAFDGX6/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QVM4UJ3376I6ZVOYMHBNX4GY3NIV52WV/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://security.gentoo.org/glsa/202107-05'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://security.netapp.com/advisory/ntap-20210625-0002/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://security.netapp.com/advisory/ntap-20211022-0004/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.oracle.com/security-alerts/cpuapr2022.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.oracle.com/security-alerts/cpujan2022.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.oracle.com/security-alerts/cpujul2022.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.oracle.com/security-alerts/cpuoct2021.html'
    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: 0.16986
epssPercentile: 0.97011
ingestedAt: '2026-10-14T10:25:41.190Z'
---

## Overview

There is a flaw in the xml entity encoding functionality of libxml2 in versions before 2.9.11. An attacker who is able to supply a crafted file to be processed by an application linked with the affected functionality of libxml2 could trigger an out-of-bounds read. The most likely impact of this flaw is to application availability, with some potential impact to confidentiality and integrity if an attacker is able to use memory information to further exploit the application.

## Affected

- `libxml2 < 2.9.11`
- `jboss_core_services`
- `enterprise_linux = 8.0`
- `fedora = 33`
- `fedora = 34`
- `debian_linux = 9.0`
- `active_iq_unified_manager`
- `clustered_data_ontap`
- `clustered_data_ontap_antivirus_connector`
- `e-series_santricity_os_controller >= 11.0.0, <= 11.70.1`
- `e-series_santricity_storage_manager`
- `e-series_santricity_web_services`
- `hci_management_node`
- `manageability_software_development_kit`
- `oncommand_insight`
- `oncommand_workflow_automation`
- `ontap_select_deploy_administration_utility`
- `santricity_unified_manager`
- `snapdrive`
- `snapmanager`
- `solidfire`
- `hci_h410c_firmware`
- `communications_cloud_native_core_network_function_cloud_native_environment = 1.10.0`
- `enterprise_manager_base_platform = 13.4.0.0`
- `enterprise_manager_base_platform = 13.5.0.0`
- `mysql_workbench <= 8.0.26`
- `openjdk = 8`
- `peoplesoft_enterprise_peopletools = 8.58`
- `real_user_experience_insight = 13.4.1.0`
- `real_user_experience_insight = 13.5.1.0`
- `zfs_storage_appliance_kit = 8.8`

## Remediation

Upgrade past the affected range:

- `libxml2 2.9.11`
