CVE-2026-56405 is an integer overflow (CWE-190) vulnerability in the libexpat project affecting versions prior to 2.8.2. The issue occurs in the getAttributeId function, where an integer overflow or wraparound can happen. This vulnerability has a CVSS 3.1 base score of 6.9, indicating a medium severity with local attack vector, high attack complexity, no privileges required, no user interaction, unchanged scope, and high impact on confidentiality and integrity with low impact on availability. No official fix or patch has been confirmed as of the publication date.

Successful exploitation of this integer overflow could lead to unauthorized disclosure or modification of data (high confidentiality and integrity impact) with limited impact on system availability. The attack requires local access and has high complexity, reducing the likelihood of exploitation. No known exploits are reported in the wild.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, users should monitor libexpat project communications for updates. No specific workaround or temporary fix is documented.