CVE-2026-41080
libexpat: expat: libexpat: Denial of Service via hash flooding with crafted XML
Severity
LowRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · April 17, 2026
Updated · July 14, 2026
Description
A flaw was found in libexpat. A remote attacker could exploit this vulnerability by providing a specially crafted XML document that leverages insufficient entropy in the hash function. This can lead to hash flooding, a type of Denial of Service (DoS) attack, where the system becomes unresponsive or crashes due to excessive resource consumption.
Statement
This Low impact denial of service flaw in libexpat could allow a remote attacker to cause the program consuming libexpat to become unresponsive or crash. This vulnerability requires the processing of a specially crafted XML document, which could lead to excessive resource consumption due to hash flooding.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Applications that process untrusted XML documents using libexpat should implement robust input validation to filter out malicious XML structures. Restricting access to services that process untrusted XML can also reduce the attack surface. If a service is affected, restarting it may be required after implementing input validation or access restrictions.
CVSS / CWE
CVSS 3.1 · 3.7CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
CWE-331 · Insufficient Entropy