Vulnerability in Libexpat Project
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 libexpat to 2.8.0 or later and applying this patch.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.007 (51.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 51st percentile — 51.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000
Affected products
- Libexpat Project
- Python — versions 3.15.0
- Python Software Foundation Cpython — versions 3.14.0, 0, 3.13.0
Weakness classification (CWE)
References
- mail.python.org/archives/list/security-announce@python.org/thread/PNY5OMBDPM2FR… (vendor-advisory, Mailing List, Third Party Advisory)
- github.com/python/cpython/pull/149023 (Patch, patch, Issue Tracking)
- github.com/python/cpython/issues/149018 (issue-tracking, Issue Tracking)
- af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)
- af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)
- github.com/python/cpython/commit/24b8f12544468e4cedf5bfbe25442fcd495391e4 (Patch, patch)
- github.com/python/cpython/commit/3573b3b1ecbd99030a0b18658e1bfece771b2566 (Patch, patch)
- github.com/python/cpython/commit/eeea765cb9d8f1fc3d8918b272ac3c477983f27a (Patch, patch)
- github.com/python/cpython/commit/fc9b11ff49cbc82e6f917d07a61517a2b5f3145f (Patch, patch)
- github.com/python/cpython/commit/e37df2a6a71d6538698e2d3188a7c345b827640b (patch)
Frequently asked questions
- What is CVE-2026-7210?
- CVE-2026-7210 is a high-severity vulnerability in Libexpat Project, classified under Insufficient Entropy. CVSS score: 7.5/10. Published 2026-05-11.
- How severe is CVE-2026-7210?
- High severity. CVSS v3 base score is 7.5 out of 10.