CVE-2026-4224
Stack overflow parsing XML with deeply nested DTD content models
CVSS Score
0.0
EPSS Score
0.0%
EPSS Percentile
5th
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.
| Vendor | python software foundation |
| Product | cpython |
| Published | Mar 16, 2026 |
| Last Updated | Apr 8, 2026 |
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Affected Versions
Python Software Foundation / CPython
0 < 3.13.13 3.14.0 < 3.14.4 3.15.0a1 < 3.15.0a8
References
github.com: https://github.com/python/cpython/commit/eb0e8be3a7e11b87d198a2c3af1ed0eccf532768 mail.python.org: https://mail.python.org/archives/list/[email protected]/thread/5M7CGUW3XBRY7II4DK43KF7NQQ3TPZ6R/ github.com: https://github.com/python/cpython/issues/145986 github.com: https://github.com/python/cpython/pull/145987 github.com: https://github.com/python/cpython/commit/196edfb06a7458377d4d0f4b3cd41724c1f3bd4a github.com: https://github.com/python/cpython/commit/e0a8a6da90597a924b300debe045cdb4628ee1f3 github.com: https://github.com/python/cpython/commit/642865ddf4b232da1f3b1f7abcfa3254c4bfe785 github.com: https://github.com/python/cpython/commit/af856a7177326ac25d9f66cc6dd28b554d914fee openwall.com: http://www.openwall.com/lists/oss-security/2026/03/16/4
Credits
🔍 Gil Portnoy Stan Ulbrych Bénédikt Tran Stan Ulbrych