RHSA-2021:2569MediumCVSS 8.6

Red Hat Security Advisory: libxml2 security update

Published
June 29, 2021
Last Modified
October 14, 2026

🔗 CVE IDs covered (5)

CVE-2021-3518 →CVE-2021-3537 →CVE-2021-3541 →CVE-2021-3516 →CVE-2021-3517 →

📋 Description

CVE-2021-3516 — libxml2: Use-after-free in xmlEncodeEntitiesInternal() in entities.c CVE-2021-3517 — libxml2: Heap-based buffer overflow in xmlEncodeEntitiesInternal() in entities.c CVE-2021-3518 — libxml2: Use-after-free in xmlXIncludeDoProcess() in xinclude.c CVE-2021-3537 — libxml2: NULL pointer dereference when post-validating mixed content parsed in recovery mode CVE-2021-3541 — libxml2: Exponential entity expansion attack bypasses all existing protection mechanisms

🎯 Affected products47

  • Red Hat Enterprise Linux AppStream (v. 8)
  • Red Hat Enterprise Linux BaseOS (v. 8)
  • libxml2-0:2.9.7-9.el8_4.2.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • libxml2-0:2.9.7-9.el8_4.2.i686 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • libxml2-0:2.9.7-9.el8_4.2.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • libxml2-0:2.9.7-9.el8_4.2.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • libxml2-0:2.9.7-9.el8_4.2.src as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • libxml2-0:2.9.7-9.el8_4.2.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • libxml2-debuginfo-0:2.9.7-9.el8_4.2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 8)
  • libxml2-debuginfo-0:2.9.7-9.el8_4.2.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • libxml2-debuginfo-0:2.9.7-9.el8_4.2.i686 as a component of Red Hat Enterprise Linux AppStream (v. 8)
  • libxml2-debuginfo-0:2.9.7-9.el8_4.2.i686 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • libxml2-debuginfo-0:2.9.7-9.el8_4.2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 8)
  • libxml2-debuginfo-0:2.9.7-9.el8_4.2.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • libxml2-debuginfo-0:2.9.7-9.el8_4.2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 8)
  • libxml2-debuginfo-0:2.9.7-9.el8_4.2.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • libxml2-debuginfo-0:2.9.7-9.el8_4.2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 8)
  • libxml2-debuginfo-0:2.9.7-9.el8_4.2.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • libxml2-debugsource-0:2.9.7-9.el8_4.2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 8)
  • libxml2-debugsource-0:2.9.7-9.el8_4.2.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • libxml2-debugsource-0:2.9.7-9.el8_4.2.i686 as a component of Red Hat Enterprise Linux AppStream (v. 8)
  • libxml2-debugsource-0:2.9.7-9.el8_4.2.i686 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • libxml2-debugsource-0:2.9.7-9.el8_4.2.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 8)
  • libxml2-debugsource-0:2.9.7-9.el8_4.2.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • libxml2-debugsource-0:2.9.7-9.el8_4.2.s390x as a component of Red Hat Enterprise Linux AppStream (v. 8)
  • libxml2-debugsource-0:2.9.7-9.el8_4.2.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • libxml2-debugsource-0:2.9.7-9.el8_4.2.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 8)
  • libxml2-debugsource-0:2.9.7-9.el8_4.2.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 8)
  • libxml2-devel-0:2.9.7-9.el8_4.2.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 8)
  • libxml2-devel-0:2.9.7-9.el8_4.2.i686 as a component of Red Hat Enterprise Linux AppStream (v. 8)
  • +17 more not shown

✅ Remediation

For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 The desktop must be restarted (log out, then log back in) for this update to take effect. Workaround: This flaw can be mitigated by not using xmllint with the --html and --push options together.

🔗 References (8)