What is CVE-2026-7210?

CVE-2026-7210 is a critical-severity vulnerability in Libexpat_project Libexpat, classified under Insufficient Entropy. CVSS score: 9.8/10. Published 2026-05-11.

How severe is CVE-2026-7210?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Vulnerability in Libexpat_project Libexpat

CVE-2026-7210

`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 li…

EPSS: 0.001 (22.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Libexpat_project Libexpat
Python
Python Software Foundation Cpython — versions 0

Weakness classification (CWE)

CWE-331 — Insufficient Entropy

References

cna@python.org (vendor-advisory, Mailing List, Third Party Advisory)
cna@python.org (Patch, patch, Issue Tracking)
cna@python.org (issue-tracking, Issue Tracking)
af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)
af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2026-7210?: CVE-2026-7210 is a critical-severity vulnerability in Libexpat_project Libexpat, classified under Insufficient Entropy. CVSS score: 9.8/10. Published 2026-05-11.
How severe is CVE-2026-7210?: Critical severity. CVSS v3 base score is 9.8 out of 10.