CVE-2026-7210

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.

Overview

State: PUBLISHED
Assigner (CNA): PSF
CVSS severity: MEDIUM
CVSS score: 6.3 / 10
CVSS 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
Effective score: 6.3 / 10 MEDIUM source: CNA overview
CWE(s): CWE-331
Reserved: 2026-04-27
Published: 2026-05-11 19:19 UTC
Last updated: 2026-05-11 22:34 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/7xxx/CVE-2026-7210.json
Linked Threat: CVE-2026-7210 — CVE-2026-7210

NVD triage scoring NVD CVE 2.0

Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.

NVD published: 2026-05-11 18:16:42 UTC
NVD last modified: 2026-05-16 03:05:17 UTC
NVD CVSS v3.1: 9.8 / 10 CRITICAL source: nvd@nist.gov
NVD CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Exploitability subscore: 3.9 / 10
Impact subscore: 5.9 / 10
EPSS score: 0.0006 (probability of exploitation in next 30 days)
EPSS percentile: 19.18% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24

European Union Vulnerability Database ENISA EUVD

ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.

EUVD ID: EUVD-2026-29178
Assigner: PSF
Published: May 11, 2026, 5:19:09 PM
Updated: May 11, 2026, 8:34:17 PM
EUVD base score (CVSS 4.0): 6.3 / 10
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
EUVD-reported EPSS: 0.0600
Vendors: Python Software Foundation
Products: CPython (0 <3.15.0)

ENISA 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.

EUVD references (3)

Microsoft Security Response Center MSRC

Microsoft's vendor-authoritative record from the Security Update Guide — its own CVSS score, impact, severity rating, exploit assessment, and KB-article fixes. Refreshed 2026-08-12 01:09 UTC (source: CVRF).

MS severity: Low
Release: 2026-May

Affected products (1)

Vendor	Product	Versions	Platforms
Python Software Foundation	CPython	`0` (affected)	—

Affected products — CPE 2.3 (1) NVD

NVD's normalized CPE 2.3 matchers, used by vendor tools (vulnerability scanners, asset managers) for automated detection. Compare with the CNA's free-text "Affected products" section above.

cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:*

Vendor references (3)

References embedded in the original CVE record by the assigning CNA.

https://mail.python.org/archives/list/security-announce@python.org/thread/PNY5OMBDPM2FRUZTWFFPJ6LISWKV627K/ vendor-advisory
https://github.com/python/cpython/pull/149023 patch
https://github.com/python/cpython/issues/149018 issue-tracking

MITRE references (3) cveawg.mitre.org

Pulled from MITRE's CVE Services API by the 🛰 Backfill from MITRE button.

https://github.com/python/cpython/pull/149023 patch
https://mail.python.org/archives/list/security-announce@python.org/thread/PNY5OMBDPM2FRUZTWFFPJ6LISWKV627K/ vendor-advisory
https://github.com/python/cpython/issues/149018 issue-tracking

Web references (6)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

MSRC update guide: CVE-2026-7210 msrc
http://www.openwall.com/lists/oss-security/2026/05/11/8 tenable:www.openwall.com
http://www.openwall.com/lists/oss-security/2026/05/11/13 tenable:www.openwall.com
https://nvd.nist.gov/vuln/detail/CVE-2026-7210 tenable:nvd.nist.gov
https://www.cve.org/CVERecord?id=CVE-2026-7210 tenable:www.cve.org
https://www.first.org/epss/ tenable:www.first.org

NVD-tagged references (5)

Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.

http://www.openwall.com/lists/oss-security/2026/05/11/13 af854a3a-2127-422b-91ae-364da2661108 Mailing ListThird Party Advisory
http://www.openwall.com/lists/oss-security/2026/05/11/8 af854a3a-2127-422b-91ae-364da2661108 Mailing ListThird Party Advisory
https://github.com/python/cpython/issues/149018 cna@python.org Issue Tracking
https://github.com/python/cpython/pull/149023 cna@python.org Issue TrackingPatch
https://mail.python.org/archives/list/security-announce@python.org/thread/PNY5OMBDPM2FRUZTWFFPJ6LISWKV627K/ cna@python.org Mailing ListThird Party Advisory

Remediations (17)

Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.

CVE-2026-7210 - Vulnerability Details - OpenCVE

web:app.opencve.io

No vendor fix or workaround currently provided. OpenCVE Recommended Actions Update the libexpat library to version 2.8.0 or newer to provide sufficient randomness in the hash‑flooding guard. Upgrade CPython to a release that includes the upstream patch for the XML parsers, or apply the patch manually to the `xml` package sources and rebuild the interpreter. Deploy the updated interpreter and ...

2026-05-23 21:01 UTC
Microsoft Releases Mitigation for Windows BitLocker Security Bypass 0 ...

web:cybersecuritynews.com

No patch has been released yet; Microsoft has instead issued a multi-step manual mitigation guide while a formal security update is prepared. Windows BitLocker Security Bypass The vulnerability originates in WinRE's handling of the BootExecute registry value under HKLM\ControlSet001\Control\Session Manager.

2026-05-23 21:01 UTC
Windows BitLocker Vulnerability (CVE-2025-21210) Exploited in ...

web:dailysecurityreview.com

A critical Windows BitLocker vulnerability ( CVE -2025-21210) allows attackers with physical access to bypass AES-XTS encryption, exposing sensitive data through a novel randomization attack.

2026-05-23 21:01 UTC
Security Update Guide - Microsoft

web:portal.msrc.microsoft.com

The Security Update Guide provides information on the latest Microsoft security updates, helping users understand and address potential vulnerabilities effectively.

2026-05-23 21:01 UTC
Patch Tuesday Vulnerability Insights - Action1

web:www.action1.com

This Patch Tuesday brings 55 vulnerability fixes from Microsoft, including six zero-days. Third-party overview includes actively exploited vulnerabilities in web browsers, Cisco, Fortinet, ServiceNow, Palo Alto, SAP, WordPress, Adobe, Oracle, and many more.

2026-05-23 21:01 UTC
CVE: Common Vulnerabilities and Exposures

web:www.cve.org

At cve .org, we provide the authoritative reference method for publicly known information-security vulnerabilities and exposures

2026-05-23 21:01 UTC
Windows 10 (KB5062554 / KB5062557 / KB5062560 / KB5062561) July 2025 ...

web:www.neowin.net

Microsoft has released July 2025 Patch Tuesday cumulative updates for Windows 10 version 21H2 and version 22H2 under KB5062554. There are also new updates for older Windows 10 versions.

2026-05-23 21:01 UTC
Microsoft Rolls Out Mitigations for 'YellowKey' BitLocker ...

web:www.securityweek.com

Microsoft has announced mitigations for CVE - 2026 -45585, a BitLocker bypass triggered via FsTx in Windows Recovery.

2026-05-23 21:01 UTC
CVE-2026-7210 | Tenable®

web:www.tenable.com

`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 .

2026-05-23 21:01 UTC
Patch Tuesday May 2026: Security Updates & CVE Analysis

web:zecurit.com

Get the complete breakdown of Microsoft's May 2026 Patch Tuesday. We analyze the latest security updates and all critical CVEs .

2026-05-23 21:01 UTC
Security Update Guide - Microsoft

web:msrc.microsoft.com

The Microsoft Security Response Center (MSRC) investigates all reports of security vulnerabilities affecting Microsoft products and services, and provides the information here as part of the ongoing effort to help you manage security risks and help keep your systems protected.

2026-05-26 02:49 UTC
CVE-2026-7210 - security-tracker.debian.org

web:security-tracker.debian.org

Vulnerable and fixed packages The table below lists information on source packages.

2026-05-26 02:49 UTC
CVE-2026-7210 | Ubuntu

web:ubuntu.com

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 .

2026-05-26 02:49 UTC
CVE-2026-7210 - vulmon.com

web:vulmon.com

Vulnerability details of CVE-2026-7210 CVE-2026-7210 - Hash Flooding Vulnerability in xml.parsers.expat and xml.etree.ElementTree

2026-05-26 02:49 UTC
Oracle Critical Patch Update Advisory - April 2026

web:www.oracle.com

This Critical Patch Update contains 481 new security patches across the product families listed below. Please note that an MOS note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at April 2026 Critical Patch Update: Executive Summary and Analysis.

2026-05-26 02:49 UTC
CVE-2026-21510: Windows 10 1607 Auth Bypass Vulnerability

web:www.sentinelone.com

CVE - 2026 -21510 is an authentication bypass vulnerability in Windows 10 1607. Learn about its impact, affected versions, and mitigation methods.

2026-05-26 02:49 UTC
CVE-2026-7210 - Critical Vulnerability - TheHackerWire

web:www.thehackerwire.com

How severe is CVE-2026-7210 ? What Libexpat Project products are affected by CVE-2026-7210 ? How do I fix or mitigate CVE-2026-7210 ? When was CVE-2026-7210 disclosed?

2026-05-26 02:49 UTC

AI Forensic Analysis

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-7210.json.

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