CVE-2026-97689

A flaw was found in urllib3. This flaw allows a Denial of Service (DoS) through unbounded memory allocation when parsing chunk-encoded responses. A malicious server can send an excessively long chunk-size line without a newline, exhausting client memory and terminating the application.

This vulnerability is rated as an Important impact because an untrusted remote server can trigger process crashes and complete denial of service across client applications without requiring authentication or special privileges. In Red Hat environments, urllib3 is integrated across numerous system tools, container workloads, and platform services to handle outbound web communication. The risk specifically manifests when these services process streamed replies from potentially malicious third-party endpoints, whereas workloads restricted to internal or verified infrastructure remain largely unaffected.

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.