High severity · published May 11, 2026
CVE-2026-7210
The expat and elementtree parsers use insufficient entropy for XML hash-flooding protection
7.5
CVSS
0.7%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.7% · higher than 52% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CP
CPython · Python Software Foundation
before 3.10.22; 3.11.0 before 3.11.16; 3.12.0 before 3.12.14; 3.13.0 before 3.13.14; 3.14.0 before 3.14.6; 3.15.0a1 before 3.15.0b2 · source: vendor
PY
Python · Python
before 3.13.14; 3.14.0 before 3.14.6; 3.15.0; 3.15.0; 3.15.0; 3.15.0; +5 more · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-7210
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-7210
vendor-advisory
https://mail.python.org/archives/list/security-announce@python.org/thread/PNY5OMBDPM2FRUZTWFFPJ6LISWKV627K/
patch
https://github.com/python/cpython/pull/149023
issue-tracking
https://github.com/python/cpython/issues/149018
patch
https://github.com/python/cpython/commit/24b8f12544468e4cedf5bfbe25442fcd495391e4
patch
https://github.com/python/cpython/commit/3573b3b1ecbd99030a0b18658e1bfece771b2566
patch
https://github.com/python/cpython/commit/eeea765cb9d8f1fc3d8918b272ac3c477983f27a
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