HighCVE-2026-7210

    The expat and elementtree parsers use insufficient entropy for XML hash-flooding protection (CVE-2026-7210)

    Published Last modified Sources: SUSE, BSI, CVE.org, Msrc Update Guide, Ubuntu, OSV, Red Hat, EUVD

    What is affected, what to do

    `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.

    Update Python Software Foundation CPython to version 3.10.22, Python Software Foundation CPython to version 3.11.16, Python Software Foundation CPython to version 3.12.14.

    Affected
    • Python Software Foundation CPython lt *..3.10.22
    • Python Software Foundation CPython lt 3.11.0..3.11.16
    • Python Software Foundation CPython lt 3.12.0..3.12.14
    • Python Software Foundation CPython lt 3.13.0..3.13.14
    • Python Software Foundation CPython lt 3.14.0..3.14.6
    • Python Software Foundation CPython lt 3.15.0a1..3.15.0b2
    Fixed in
    • Python Software Foundation CPython 3.10.22
    • Python Software Foundation CPython 3.11.16
    • Python Software Foundation CPython 3.12.14
    • Python Software Foundation CPython 3.13.14
    • Python Software Foundation CPython 3.14.6
    • Python Software Foundation CPython 3.15.0b2

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    7.5

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: NVD, CVSS v3

    7.5

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: SUSE, BSI, CVE.org, Msrc Update Guide, Ubuntu, OSV, Red Hat, EUVD

    0.7 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 51.8

    Show all metrics
    Severity
    High
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    76.36 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    no public PoC known
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    7.5 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    7.5
    CVSS v4

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    6.3
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

    Read in glossary
    0.7 %
    Low — model estimates < 1% exploitation likelihood.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    51.8
    High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    —
    Published
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-331

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    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.

    Source: suse_csaf, BSI WID Portal, BSI CSAF, NVD (NIST), Microsoft Security Update Guide, Ubuntu Security Notices, CVE.org (MITRE), cvelistv5, OSV (Open Source Vulnerabilities), redhat_csaf, ENISA EUVD

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    Python Software FoundationCPython
    • 3.12.0 – < 3.12.14
    • 3.11.0 – < 3.11.16
    • 3.14.0 – < 3.14.6
    • 3.13.0 – < 3.13.14
    • < 3.10.22
    • 3.15.0a1 – < 3.15.0b2
    • 3.12.14
    • 3.11.16
    • 3.14.6
    • 3.13.14
    • 3.10.22
    • 3.15.0b2
    pythonpython
    • < 3.13.14
    • 3.15.0
    • 3.14.0 – < 3.14.6
    • 3.13.14
    • —
    • 3.14.6
    Open SourcePython CPython
    • < 2.8.0
    • 2.8.0
    Distribution and container packages (4)

    Downstream packages (e.g. Bitnami, Debian, Ubuntu, Red Hat). Versions refer to the distribution, not the vendor.

    Distribution and container packages
    Affected versionsFixed in
    bitnamipython-min
    • 3.13.0
    • 3.12.0
    • 3.14.0
    • 3.11.0
    • —
    • —
    • —
    • —

    Vendors and products

    Weakness classes (CWE)

    • CWE-331Insufficient Entropy

      Base

      The product uses an algorithm or scheme that produces insufficient entropy, leaving patterns or clusters of values that are more likely to occur than others.

      Entry at MITRE CWE-331

    References & sources

    • mail.python.orgarchives/list/security-announce@python.org/thread/PNY5OMBDPM2FR…advisory, Vendor advisory, Mailing list, Third-party advisory
    • github.compython/cpython/pull/149023web, Patch, Issue tracking, Patch
    • github.compython/cpython/issues/149018report, Issue tracking, Issue tracking
    • github.compython/cpython/commit/24b8f12544468e4cedf5bfbe25442fcd495391e4fix, Patch, Patch
    • github.compython/cpython/commit/3573b3b1ecbd99030a0b18658e1bfece771b2566fix, Patch, Patch
    • github.compython/cpython/commit/eeea765cb9d8f1fc3d8918b272ac3c477983f27afix, Patch, Patch
    • github.compython/cpython/commit/fc9b11ff49cbc82e6f917d07a61517a2b5f3145ffix, Patch, Patch
    • github.compython/cpython/commit/e37df2a6a71d6538698e2d3188a7c345b827640bPatch
    • openwall.comlists/oss-security/2026/05/11/8Mailing list, Third-party advisory
    • openwall.comlists/oss-security/2026/05/11/13Mailing list, Third-party advisory
    • github.compython/cpython/commit/cbaecf9f16da611a646d507c1cbca265c588fc56Patch
    • github.compython/cpython/commit/ea70712d1a8508e14e9677d44f838dab04dc0286Patch
    • NVD (NIST)vuln/detail/CVE-2026-7210web

    Changes to this CVE

    Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

    1. Record modifiedpython.org

      Show 28 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)added
      —
      Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/7xxx/CVE-2026-7210.json">CVE-2026-7210</a>
      Referenceadded
      —
      https://github.com/python/cpython/commit/24b8f12544468e4cedf5bfbe25442fcd495391e4
      Referenceadded
      —
      https://github.com/python/cpython/commit/3573b3b1ecbd99030a0b18658e1bfece771b2566
      Referenceadded
      —
      https://github.com/python/cpython/commit/cbaecf9f16da611a646d507c1cbca265c588fc56
      Referenceadded
      —
      https://github.com/python/cpython/commit/e37df2a6a71d6538698e2d3188a7c345b827640b
      Referenceadded
      —
      https://github.com/python/cpython/commit/ea70712d1a8508e14e9677d44f838dab04dc0286
      Referenceadded
      —
      https://github.com/python/cpython/commit/eeea765cb9d8f1fc3d8918b272ac3c477983f27a
      Referenceadded
      —
      https://github.com/python/cpython/commit/fc9b11ff49cbc82e6f917d07a61517a2b5f3145f
      Referenceadded
      —
      https://github.com/python/cpython/issues/149018
      Referenceadded
      —
      https://github.com/python/cpython/pull/149023
      Referenceadded
      —
      https://mail.python.org/archives/list/security-announce@python.org/thread/PNY5OMBDPM2FRUZTWFFPJ6LISWKV627K/
      Referenceremoved
      https://github.com/python/cpython/commit/24b8f12544468e4cedf5bfbe25442fcd495391e4
      —
      Referenceremoved
      https://github.com/python/cpython/commit/3573b3b1ecbd99030a0b18658e1bfece771b2566
      —
      Referenceremoved
      https://github.com/python/cpython/commit/cbaecf9f16da611a646d507c1cbca265c588fc56
      —
      Referenceremoved
      https://github.com/python/cpython/commit/e37df2a6a71d6538698e2d3188a7c345b827640b
      —
      Referenceremoved
      https://github.com/python/cpython/commit/ea70712d1a8508e14e9677d44f838dab04dc0286
      —
      Referenceremoved
      https://github.com/python/cpython/commit/eeea765cb9d8f1fc3d8918b272ac3c477983f27a
      —
      Referenceremoved
      https://github.com/python/cpython/commit/fc9b11ff49cbc82e6f917d07a61517a2b5f3145f
      —
      Referenceremoved
      https://github.com/python/cpython/issues/149018
      —
      Referenceremoved
      https://github.com/python/cpython/pull/149023
      —
      Referenceremoved
      https://mail.python.org/archives/list/security-announce@python.org/thread/PNY5OMBDPM2FRUZTWFFPJ6LISWKV627K/
      —
      Reference typeremoved
      https://github.com/python/cpython/commit/24b8f12544468e4cedf5bfbe25442fcd495391e4 Types: Patch
      —
      Reference typeremoved
      https://github.com/python/cpython/commit/3573b3b1ecbd99030a0b18658e1bfece771b2566 Types: Patch
      —
      Reference typeremoved
      https://github.com/python/cpython/commit/eeea765cb9d8f1fc3d8918b272ac3c477983f27a Types: Patch
      —
      Reference typeremoved
      https://github.com/python/cpython/commit/fc9b11ff49cbc82e6f917d07a61517a2b5f3145f Types: Patch
      —
      Reference typeremoved
      https://github.com/python/cpython/issues/149018 Types: Issue Tracking
      —
      Reference typeremoved
      https://github.com/python/cpython/pull/149023 Types: Issue Tracking, Patch
      —
      Reference typeremoved
      https://mail.python.org/archives/list/security-announce@python.org/thread/PNY5OMBDPM2FRUZTWFFPJ6LISWKV627K/ Types: Mailing List, Third Party Advisory
      —

      Source identifier: cna@python.org

    2. Record modifiedCVE Program

      Show 6 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      http://www.openwall.com/lists/oss-security/2026/05/11/13
      Referenceadded
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      http://www.openwall.com/lists/oss-security/2026/05/11/8
      Referenceremoved
      http://www.openwall.com/lists/oss-security/2026/05/11/13
      —
      Referenceremoved
      http://www.openwall.com/lists/oss-security/2026/05/11/8
      —
      Reference typeremoved
      http://www.openwall.com/lists/oss-security/2026/05/11/13 Types: Mailing List, Third Party Advisory
      —
      Reference typeremoved
      http://www.openwall.com/lists/oss-security/2026/05/11/8 Types: Mailing List, Third Party Advisory
      —

      Source identifier: af854a3a-2127-422b-91ae-364da2661108

    3. Record modifiedpython.org

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://github.com/python/cpython/commit/e37df2a6a71d6538698e2d3188a7c345b827640b

      Source identifier: cna@python.org

    4. NVD analysis modifiedNVD

      Product mapping changed:
      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Product configurationchanged
      OR *cpe:2.3:a:python:python:*:*:*:*:*:*:*:* versions up to (excluding) 3.15.0
      OR *cpe:2.3:a:python:python:3.15.0:alpha1:*:*:*:*:*:* *cpe:2.3:a:python:python:3.15.0:alpha2:*:*:*:*:*:* *cpe:2.3:a:python:python:3.15.0:alpha3:*:*:*:*:*:* *cpe:2.3:a:python:python:3.15.0:alpha4:*:*:*:*:*:* *cpe:2.3:a:python:python:3.15.0:alpha5:*:*:*:*:*:* *cpe:2.3:a:python:python:3.15.0:alpha6:*:*:*:*:*:* *cpe:2.3:a:python:python:3.15.0:alpha7:*:*:*:*:*:* *cpe:2.3:a:python:python:3.15.0:alpha8:*:*:*:*:*:* *cpe:2.3:a:python:python:*:*:*:*:*:*:*:* versions up to (excluding) 3.13.14 *cpe:2.3:a:python:python:*:*:*:*:*:*:*:* versions from (including) 3.14.0 up to (excluding) 3.14.6 *cpe:2.3:a:python:python:3.15.0:beta1:*:*:*:*:*:*

      Source identifier: nvd@nist.gov

    5. NVD analysis modifiedNVD

      CVSS V3.1: AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

      CVSS V3.1: before AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H, after —

      Show 6 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      CVSSadded
      —
      AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
      CVSSremoved
      AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
      —
      Reference typeadded
      —
      Python Software Foundation: https://github.com/python/cpython/commit/24b8f12544468e4cedf5bfbe25442fcd495391e4 Types: Patch
      Reference typeadded
      —
      Python Software Foundation: https://github.com/python/cpython/commit/3573b3b1ecbd99030a0b18658e1bfece771b2566 Types: Patch
      Reference typeadded
      —
      Python Software Foundation: https://github.com/python/cpython/commit/eeea765cb9d8f1fc3d8918b272ac3c477983f27a Types: Patch
      Reference typeadded
      —
      Python Software Foundation: https://github.com/python/cpython/commit/fc9b11ff49cbc82e6f917d07a61517a2b5f3145f Types: Patch

      Source identifier: nvd@nist.gov

    Show one older change

    1. Record modifiedpython.org

      Show 4 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://github.com/python/cpython/commit/24b8f12544468e4cedf5bfbe25442fcd495391e4
      Referenceadded
      —
      https://github.com/python/cpython/commit/3573b3b1ecbd99030a0b18658e1bfece771b2566
      Referenceadded
      —
      https://github.com/python/cpython/commit/eeea765cb9d8f1fc3d8918b272ac3c477983f27a
      Referenceadded
      —
      https://github.com/python/cpython/commit/fc9b11ff49cbc82e6f917d07a61517a2b5f3145f

      Source identifier: cna@python.org

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    <a href="https://intel.neosec.eu/en/cve/CVE-2026-7210"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-7210.svg?lang=en" alt="CVE-2026-7210 – NEOSEC Intel" height="20"></a>