RHSA-2026:93473 - Security Advisory

Topic

An update for libxml2 is now available for Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support and Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On.

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: Stack Buffer Overflow in xmllint Interactive Shell Command Handling (CVE-2025-6170)
• 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):

• libxml2: CVE-2025-9714 fix (RHEL-131761) backported wrong upstream commit ? dyn:map recursion still crashes (JIRA:RHEL-277436)

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 Life Cycle Long Life 8.4 x86_64
• Red Hat Enterprise Linux Server - AUS 8.4 x86_64

Fixes

• BZ - 2372952 - CVE-2025-6170 libxml2: Stack Buffer Overflow in xmllint Interactive Shell Command Handling
• 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
• RHEL-277436 - libxml2: CVE-2025-9714 fix (RHEL-131761) backported wrong upstream commit ? dyn:map recursion still crashes [rhel-8.4.0.z]

CVEs

• CVE-2025-6170
• 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