CVE-2016-1839: The xmlDictAddString function in libxml2 before 2.9.4, as used in Apple iOS before 9.3.2, OS X before 10.11...

Security readout for executives and security teams

CVE-2016-1839 is a denial-of-service flaw in libxml2 before 2.9.4. A malicious XML document can make software using the vulnerable parser read past a heap buffer and crash or become unavailable. It matters most where untrusted XML is processed. Exposure is likely in systems or applications using libxml2 before 2.9.4, especially internet-facing XML parsers or products bundling the library. Confirm Apple versions before iOS 9.3.2, OS X 10.11.5, tvOS 9.2.1, and watchOS 2.2.1. Treat this as a practical availability risk, not a confirmed breach indicator. Patch during normal vulnerability remediation, escalating for public services or critical workflows that parse external XML. Mitigation focus: Upgrade libxml2 to 2.9.4 or a vendor-supported fixed package.; Apply Apple, Debian, Red Hat, Ubuntu, Oracle, or product-specific advisories where applicable.; Prioritize systems parsing untrusted XML from users, partners, or the internet..

Prepared

Jun 13, 2026, 14:22 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.