BIT-PYTHON-2026-4224 Stack overflow parsing XML with deeply nested DTD content models

When an Expat parser with a registered ElementDeclHandler parses an inline document type definition containing a deeply nested content model a C stack overflow occurs...

BIT-PYTHON-MIN-2026-4224 Stack overflow parsing XML with deeply nested DTD content models

When an Expat parser with a registered ElementDeclHandler parses an inline document type definition containing a deeply nested content model a C stack overflow occurs...

BIT-LIBPYTHON-2026-4224 Stack overflow parsing XML with deeply nested DTD content models

When an Expat parser with a registered ElementDeclHandler parses an inline document type definition containing a deeply nested content model a C stack overflow occurs...

cpython: Stack overflow parsing XML with deeply nested DTD content models

A stack overflow flaw has been discovered in the python pyexpat module. When an Expat parser with a registered ElementDeclHandler parses an inline document type definition containing a deeply nested content model a C stack overflow occurs. This will result in a program crash...

cpython: Stack overflow parsing XML with deeply nested DTD content models

A stack overflow flaw has been discovered in the python pyexpat module. When an Expat parser with a registered ElementDeclHandler parses an inline document type definition containing a deeply nested content model a C stack overflow occurs. This will result in a program crash...

CVE-2026-4224 Stack overflow parsing XML with deeply nested DTD content models

When an Expat parser with a registered ElementDeclHandler parses an inline document type definition containing a deeply nested content model a C stack overflow occurs...

CVE-2026-4224

CVE-2026-4224 is a CPython vulnerability: when an Expat parser with a registered ElementDeclHandler parses an inline DTD containing a deeply nested content model, a C stack overflow can occur. The connected advisories confirm this affects multiple Python3 series (3.9, 3.11, 3.12, 3.13, 3.14) and ...