MEDIUM6.3
`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.
CVSS 3.xHIGH 7.5
CVSS:3.x/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVSS 4.0MEDIUM 6.3
CVSS:4.0/CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XReferences
- https://github.com/python/cpython/commit/24b8f12544468e4cedf5bfbe25442fcd495391e4
- https://github.com/python/cpython/commit/3573b3b1ecbd99030a0b18658e1bfece771b2566
- https://github.com/python/cpython/commit/eeea765cb9d8f1fc3d8918b272ac3c477983f27a
- https://github.com/python/cpython/commit/fc9b11ff49cbc82e6f917d07a61517a2b5f3145f
- https://github.com/python/cpython/issues/149018
- https://github.com/python/cpython/pull/149023
- https://mail.python.org/archives/list/security-announce@python.org/thread/PNY5OMBDPM2FRUZTWFFPJ6LISWKV627K/
- http://www.openwall.com/lists/oss-security/2026/05/11/13
- http://www.openwall.com/lists/oss-security/2026/05/11/8