RHSA-2026:90309 - Security Advisory

Topic

An update for libxml2 is now available for Red Hat Enterprise Linux 9.6 Extended Update Support.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

The libxml2 library is a development toolbox providing the implementation of various XML standards.

Security Fix(es):

• libxml2: mingw-libxml2: libxml2: Denial of Service via crafted XML input due to use-after-free (CVE-2026-6653)
• libxml2: libxml2: Arbitrary code execution in xmlcatalog utility via buffer overflow (CVE-2026-11979)
• libxml2: libxml2: Arbitrary code execution via heap-based buffer overflow (CVE-2026-86138)
• libxml2: libxml2: Data integrity issues due to integer overflow in write callbacks (CVE-2026-86143)
• libxml2: libxml2: Arbitrary code execution via stack-based buffer overflow in xmlSnprintfElements (CVE-2026-86140)
• libxml2: libxml2: Heap-based buffer overflow in xmlXPtrEval due to xpointer length saturation (CVE-2026-86142)
• libxml2: libxml2: Information disclosure, SSRF, or denial of service due to improper parseFlags propagation. (CVE-2026-86144)
• libxml2: double-free/UAF in libxml2 Python bindings (CVE-2026-74860)

Bug Fix(es) and Enhancement(s):

• sync release version across rhel-9.2/4/6 for libxml2 (JIRA:RHEL-282570)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux for x86_64 - Extended Update Support 9.6 x86_64
• Red Hat Enterprise Linux Server - AUS 9.6 x86_64
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 9.6 s390x
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 9.6 ppc64le
• Red Hat Enterprise Linux for ARM 64 - Extended Update Support 9.6 aarch64
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 9.6 ppc64le
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 9.6 x86_64
• Red Hat Enterprise Linux for ARM 64 - 4 years of updates 9.6 aarch64
• Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 9.6 s390x
• Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 9.6 x86_64
• Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 9.6 aarch64
• Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 9.6 ppc64le
• Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 9.6 s390x

Fixes

• BZ - 2491354 - CVE-2026-6653 libxml2: mingw-libxml2: libxml2: Denial of Service via crafted XML input due to use-after-free
• BZ - 2494191 - CVE-2026-11979 libxml2: libxml2: Arbitrary code execution in xmlcatalog utility via buffer overflow
• BZ - 2528986 - CVE-2026-86138 libxml2: libxml2: Arbitrary code execution via heap-based buffer overflow
• BZ - 2528987 - CVE-2026-86143 libxml2: libxml2: Data integrity issues due to integer overflow in write callbacks
• BZ - 2528989 - CVE-2026-86140 libxml2: libxml2: Arbitrary code execution via stack-based buffer overflow in xmlSnprintfElements
• BZ - 2528990 - CVE-2026-86142 libxml2: libxml2: Heap-based buffer overflow in xmlXPtrEval due to xpointer length saturation
• BZ - 2528992 - CVE-2026-86144 libxml2: libxml2: Information disclosure, SSRF, or denial of service due to improper parseFlags propagation.
• BZ - 2529697 - CVE-2026-74860 libxml2: double-free/UAF in libxml2 Python bindings

CVEs

• CVE-2026-6653
• CVE-2026-11979
• CVE-2026-74860
• CVE-2026-86138
• CVE-2026-86140
• CVE-2026-86142
• CVE-2026-86143
• CVE-2026-86144

References

• https://access.redhat.com/security/updates/classification/#important