libxml2 Heap-Based Buffer Under-Read Vulnerability in XML Schema Validation

A heap-based buffer under-read vulnerability has been identified in libxml2 versions prior to 2.13.8 and in the 2.14.x branch prior to 2.14.2. The issue arises in the 'xmlSchemaIDCFillNodeTables' function within 'xmlschemas.c'. Exploitation of this vulnerability requires a crafted XML document to be validated against an XML schema that includes specific identity constraints, or the use of a specially crafted XML schema.

Impact

Exploitation of this vulnerability can lead to a heap-based buffer under-read, which may cause information disclosure or memory corruption.