RLSA-2026:98478: Important: expat security update
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)
expat: expat: Denial of Service via integer overflow in expatrealloc (CVE-2026-102633)
expat: expat: Information disclosure via heap buffer over-read in XMLParseBuffer (CVE-2026-77214)
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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
rocky-linux/expatto a version that resolves this vulnerability.Fixed in 0:2.5.0-9.el9_9.4 - Upgrade
Upgrade
rocky-linux/expat-debuginfoto a version that resolves this vulnerability.Fixed in 0:2.5.0-9.el9_9.4 - Upgrade
Upgrade
rocky-linux/expat-debugsourceto a version that resolves this vulnerability.Fixed in 0:2.5.0-9.el9_9.4 - Upgrade
Upgrade
rocky-linux/expat-develto a version that resolves this vulnerability.Fixed in 0:2.5.0-9.el9_9.4
Event History
Child vulnerabilities
Contains the following vulnerabilities.
Frequently Asked Questions
Which installed packages are covered by this update?
The advisory covers rocky-linux/expat and its debuginfo, debugsource, and development packages: rocky-linux/expat-debuginfo, rocky-linux/expat-debugsource, and rocky-linux/expat-devel.
What could an unauthenticated remote attacker do?
The listed CVEs include denial of service through quadratic attribute processing and an integer overflow, XML injection through malformed UTF-16 input, and information disclosure through a heap buffer over-read in XML_ParseBuffer. The supplied CVSS vector indicates network reachability with low attack complexity and no privileges or user interaction required.
What types of XML input are specifically implicated?
The advisory identifies attribute processing, malformed UTF-16 input, and use of XML_ParseBuffer as affected areas. Systems that parse attacker-controlled XML through Expat are relevant to these issues.