RHSA-2026:74001 - Security Advisory

Topic

An update for expat is now available for Red Hat Enterprise Linux 10.

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

Expat is a C library for parsing XML documents.

Security Fix(es):

• expat: Expat: Denial of Service via quadratic complexity in attribute processing (CVE-2026-66046)
• expat: Expat: XML Injection via Malformed UTF-16 Input (CVE-2026-93990)

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 10 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 10.2 x86_64
• Red Hat Enterprise Linux for IBM z Systems 10 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 10.2 s390x
• Red Hat Enterprise Linux for Power, little endian 10 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 10.2 ppc64le
• Red Hat Enterprise Linux for ARM 64 10 aarch64
• Red Hat Enterprise Linux for ARM 64 - Extended Update Support 10.2 aarch64
• Red Hat Enterprise Linux for ARM 64 - 4 years of updates 10.2 aarch64
• Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 10.2 s390x
• Red Hat Enterprise Linux for Power, little endian - 4 years of support 10.2 ppc64le
• Red Hat Enterprise Linux for x86_64 - 4 years of updates 10.2 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 10.2 x86_64
• Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 10.2 aarch64
• Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 10.2 ppc64le
• Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 10.2 s390x

Fixes

• BZ - 2517901 - CVE-2026-66046 expat: Expat: Denial of Service via quadratic complexity in attribute processing
• BZ - 2538967 - CVE-2026-93990 expat: Expat: XML Injection via Malformed UTF-16 Input

CVEs

• CVE-2026-66046
• CVE-2026-93990

References

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