CVE-2026-7210
The expat and elementtree parsers use insufficient entropy for XML hash-flooding protection
- State
- Published
- Severity
- 6.3 Medium
- Published
- May 11, 2026
- Updated
- Oct 2, 2026
- Reserved
- Apr 27, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 6.3 Medium | 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 | PSF |
Weaknesses
- CWE-331 Insufficient entropy
Affected Products
| Product | Versions |
|---|---|
CPythonPython Software Foundation |
|
References
- https://mail.python.org/archives/list/security-announce@python.org/thread/PNY5OMBDPM2FRUZTWFFPJ6LISWKV627K/vendor-advisory
- https://github.com/python/cpython/pull/149023patch
- https://github.com/python/cpython/issues/149018issue-tracking
- https://github.com/python/cpython/commit/24b8f12544468e4cedf5bfbe25442fcd495391e4patch
- https://github.com/python/cpython/commit/3573b3b1ecbd99030a0b18658e1bfece771b2566patch
- https://github.com/python/cpython/commit/eeea765cb9d8f1fc3d8918b272ac3c477983f27apatch
- https://github.com/python/cpython/commit/fc9b11ff49cbc82e6f917d07a61517a2b5f3145fpatch
- https://github.com/python/cpython/commit/e37df2a6a71d6538698e2d3188a7c345b827640bpatch
- https://github.com/python/cpython/commit/cbaecf9f16da611a646d507c1cbca265c588fc56patch
- https://github.com/python/cpython/commit/ea70712d1a8508e14e9677d44f838dab04dc0286patch
- http://www.openwall.com/lists/oss-security/2026/05/11/8
- http://www.openwall.com/lists/oss-security/2026/05/11/13
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