CVE-2026-7210
Medium
Elevated severity or exploit probability.
CVSS base
7.5
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS — probability of exploitation (30 days)
1.4%
70.3th percentile
CISA KEV
Not listed
Weakness / dates
CWE-331
Published 2026-05-11 · modified 2026-08-14
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.
Affected
References
- https://github.com/python/cpython/commit/24b8f12544468e4cedf5bfbe25442fcd495391e4
- https://github.com/python/cpython/commit/3573b3b1ecbd99030a0b18658e1bfece771b2566
- https://github.com/python/cpython/commit/cbaecf9f16da611a646d507c1cbca265c588fc56
- https://github.com/python/cpython/commit/e37df2a6a71d6538698e2d3188a7c345b827640b
- https://github.com/python/cpython/commit/ea70712d1a8508e14e9677d44f838dab04dc0286
- 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