Integer Overflow Vulnerability in libexpat Affects Data Parsing

CVE-2026-56406

What is CVE-2026-56406?

The libexpat library, prior to version 2.8.2, is susceptible to an integer overflow in the XML_ParseBuffer function. This vulnerability arises due to the absence of a crucial input validation check that is implemented in the XML_Parse function. Exploiting this weakness could allow attackers to manipulate buffer sizes, potentially leading to unexpected behavior, such as memory corruption or denial of service. It is critical for organizations using affected versions of libexpat to upgrade to 2.8.2 or later to mitigate risk.

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