Description
`xml.parsers.expat` and `xml.etree.ElementTree` use insufficient entropy for Expat hash-flooding protection, which allows a crafted XML document to trigger hash flooding.\r\n\r\nFully mitigating this vulnerability requires both updating libexpat to 2.8.0 or later and applying this patch.
Problem types
Product status
Any version before 3.15.0
Credits
Stan Ulbrych (https://github.com/StanFromIreland)
Gregory P. Smith (https://github.com/gpshead)
References
www.openwall.com/lists/oss-security/2026/05/11/8
www.openwall.com/lists/oss-security/2026/05/11/13
mail.python.org/.../thread/PNY5OMBDPM2FRUZTWFFPJ6LISWKV627K/
github.com/python/cpython/pull/149023
github.com/python/cpython/issues/149018