CVE-2026-4224

Description

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.

Affected Platforms

Weakness Type

CWE-674

References

• https://github.com/python/cpython/commit/196edfb06a7458377d4d0f4b3cd41724c1f3bd4…
• https://github.com/python/cpython/commit/24ce88b285f56ee11626cf5e472af3cd8cc7c62…
• https://github.com/python/cpython/commit/642865ddf4b232da1f3b1f7abcfa3254c4bfe78…
• https://github.com/python/cpython/commit/af856a7177326ac25d9f66cc6dd28b554d914fe…
• https://github.com/python/cpython/commit/e0a8a6da90597a924b300debe045cdb4628ee1f…
• https://github.com/python/cpython/commit/eb0e8be3a7e11b87d198a2c3af1ed0eccf53276…