CVE-2026-7210
The expat and elementtree parsers use insufficient entropy for XML hash-flooding protection
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.
INFO
Published Date :
May 11, 2026, 6:16 p.m.
Last Modified :
June 1, 2026, 2:32 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-7210
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | CRITICAL | [email protected] | ||||
| CVSS 4.0 | MEDIUM | 28c92f92-d60d-412d-b760-e73465c3df22 | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Update libexpat to version 2.8.0 or later.
- Apply the relevant security patch.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-7210.
| URL | Resource |
|---|---|
| https://github.com/python/cpython/issues/149018 | Issue Tracking |
| https://github.com/python/cpython/pull/149023 | Issue Tracking Patch |
| https://mail.python.org/archives/list/[email protected]/thread/PNY5OMBDPM2FRUZTWFFPJ6LISWKV627K/ | Mailing List Third Party Advisory |
| http://www.openwall.com/lists/oss-security/2026/05/11/13 | Mailing List Third Party Advisory |
| http://www.openwall.com/lists/oss-security/2026/05/11/8 | Mailing List Third Party Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-7210 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-7210
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-7210 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-7210 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Reanalysis by [email protected]
Jun. 01, 2026
Action Type Old Value New Value Changed CPE Configuration OR *cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:* versions up to (excluding) 2.8.0 OR *cpe:2.3:a:python:python:*:*:*:*:*:*:*:* versions up to (excluding) 3.15.0 -
Initial Analysis by [email protected]
May. 16, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Added CPE Configuration OR *cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:* versions up to (excluding) 2.8.0 Added Reference Type CVE: http://www.openwall.com/lists/oss-security/2026/05/11/13 Types: Mailing List, Third Party Advisory Added Reference Type CVE: http://www.openwall.com/lists/oss-security/2026/05/11/8 Types: Mailing List, Third Party Advisory Added Reference Type Python Software Foundation: https://github.com/python/cpython/issues/149018 Types: Issue Tracking Added Reference Type Python Software Foundation: https://github.com/python/cpython/pull/149023 Types: Issue Tracking, Patch Added Reference Type Python Software Foundation: https://mail.python.org/archives/list/[email protected]/thread/PNY5OMBDPM2FRUZTWFFPJ6LISWKV627K/ Types: Mailing List, Third Party Advisory -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
May. 11, 2026
Action Type Old Value New Value Added Reference http://www.openwall.com/lists/oss-security/2026/05/11/13 -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
May. 11, 2026
Action Type Old Value New Value Added Reference http://www.openwall.com/lists/oss-security/2026/05/11/8 -
New CVE Received by [email protected]
May. 11, 2026
Action Type Old Value New Value 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. Added CVSS V4.0 AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-331 Added Reference https://github.com/python/cpython/issues/149018 Added Reference https://github.com/python/cpython/pull/149023 Added Reference https://mail.python.org/archives/list/[email protected]/thread/PNY5OMBDPM2FRUZTWFFPJ6LISWKV627K/