CVE-2026-7210

The expat and elementtree parsers use insufficient entropy for XML hash-flooding protection

Published May 11, 2026 CVSS 4.0 · 6.3 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Ubuntu USN Ubuntu USN USN-8524-1 Python vulnerability
History
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Python python
CPEs cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:* cpe:2.3:a:python:python:*:*:*:*:*:*:*:*
Vendors & Products Libexpat Project
Libexpat Project libexpat
Python python
Type Values Removed Values Added
First Time appeared Libexpat Project
Libexpat Project libexpat
CPEs cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:*
Vendors & Products Libexpat Project
Libexpat Project libexpat
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
First Time appeared Python
Python cpython
Vendors & Products Python
Python cpython
Type Values Removed Values Added
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.
Title The expat and elementtree parsers use insufficient entropy for XML hash-flooding protection
Weaknesses CWE-331
References
Metrics cvssV4_0

{'score': 6.3, 'vector': '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
PSF
Published
Updated
Oct 2, 2026, 12:35 AM
Reserved
Apr 27, 2026, 2:43 PM
Status
Modified
Published
May 11, 2026, 6:16 PM
Modified
Oct 26, 2026, 6:10 PM
Severity
Moderate
Public date
May 11, 2026, 5:19 PM