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<document>
  <header>
    <title>Apache POI™ - the Java API for Microsoft Documents</title>
  </header>

  <body>
    <section><title>Project News</title>

      <section><title>7 July 2025 - Source repository switched from Subversion to Git</title>
        <p>
			Apache POI switched hosting of the source repository from Subversion to Git.
		</p>
		  <p>
			After Subversion served the project well for many years, it was time to enable more
			up-to-date workflows by using more of the features offered by Git-based platforms like
			GitHub.
		  </p>
		  <p>
			Therefore the source-code is now officially available at the previous
			read-only mirror at <a href="https://github.com/apache/poi">https://github.com/apache/poi</a>.
		  </p>
		  <p>
			This hopefully allows a smooth transition for anybody already using Git via
			the read-only mirror.
		  </p>
		  <p>
			Users who still used the Subversion-based repository will need to checkout a
			fresh copy and migrate any pending changes.
        </p>
      </section>

      <section><title>8 April 2025 - CVE-2025-31672 - Improper Input Validation vulnerability in Apache POI before 5.4.0</title>
        <p>
          While parsing of OOXML format files like xlsx, docx and pptx, a specially crafted file could
          be used to provide multiple entries with the same name in the zip-compressed file-format.
          <br/>
          Products reading the affected file could read different data because one of the zip entries with the
          duplicate name is selected over another by different products differently.<br/><br/>
          This issue affects Apache POI component poi-ooxml before 5.4.0. Starting with 5.4.0 poi-ooxml performs
          a check that throws an exception if zip entries with duplicate file names are found in the input file.<br/><br/>
          Users are recommended to upgrade to version poi-ooxml 5.4.0 or later, which fixes the issue.
          Please refer to our <a href="https://poi.apache.org/security.html">security guidelines</a>
          for recommendations about how to use the POI libraries securely.
        </p>
        <p>
          References:
        </p>
        <ul>
          <li><a href="https://bz.apache.org/bugzilla/show_bug.cgi?id=69620">Bug 69620</a></li>
          <li><a href="https://www.cve.org/CVERecord?id=CVE-2025-31672">CVE-2025-31672</a></li>
        </ul>
      </section>

      <!-- latest final release -->
      <section><title>6 April 2025 - POI 5.4.1 available</title>
        <p>The Apache POI team is pleased to announce the release of 5.4.1.
          Several dependencies were updated to their latest versions to pick up security fixes and other improvements.</p>
        <p>A summary of changes is available in the
          <a href="https://www.apache.org/dyn/closer.lua/poi/release/RELEASE-NOTES.txt">Release Notes</a>.
          A full list of changes is available in the <a href="changes.html#5.4.1">change log</a>.
          People interested should also follow the <a href="site:mailinglists">dev list</a> to track progress.</p>
        <p>See the <a href="download.html#POI-5.4.1">downloads</a> page for more details.</p>
        <p>POI requires Java 8 or newer since version 4.0.1.</p>
      </section>

      <section><title>11 November 2024 - Avoid log4j-api 2.24.1</title>
        <p>While testing a potential Apache POI 5.4.0 release, we discovered a serious bug in
        log4j-api 2.24.1. This leads to NullPointerExceptions when you use a version of log4j-core that is not of
        the exact same version (2.24.1). We recommend that users avoid log4j 2.24.1 and use the latest
          2.24.x version where this issue is fixed again.</p>
        <p>XMLBeans release 5.2.2 had the problematic log4j-api 2.24.1 dependency and thus
          can lead to such issues if used in some other context. In the meantime a version 5.3.0
          of XmlBeans was released which avoids this issue.</p>
        <p>Please direct any queries to the Log4j Team. The main issue is
          <a href="https://github.com/apache/logging-log4j2/issues/3143">Issue 3143</a>.</p>
      </section>

      <section><title>4 March 2022 - CVE-2022-26336 - A carefully crafted TNEF file can cause an out of memory exception in Apache POI poi-scratchpad versions prior to 5.2.0</title>
        <p>Description:<br/>
          A shortcoming in the HMEF package of poi-scratchpad (Apache POI) allows an attacker to cause an Out of Memory exception.
          This package is used to read TNEF files (Microsoft Outlook and Microsoft Exchange Server).
          If an application uses poi-scratchpad to parse TNEF files and the application allows untrusted users to supply them, then a carefully crafted file can cause an Out of Memory exception.</p>

        <p>Mitigation:<br/>
          Affected users are advised to update to poi-scratchpad 5.2.1 or above
          which fixes this vulnerability. It is recommended that you use the same versions of all POI jars.</p>

      </section>

      <section><title>10+16+18 December 2021- Log4j vulnerabilities CVE-2021-44228, CVE-2021-45046 and CVE-2021-45105</title>
        <p>The Apache POI PMC has evaluated the security vulnerabilities reported
            for Apache Log4j.</p>
        <p>POI 5.1.0 and XMLBeans 5.0.2 only have dependencies on log4j-api 2.14.1.
            The security vulnerabilities are not in log4j-api - they are in log4j-core.</p>
        <p>If any POI or XMLBeans user uses log4j-core to control their logging of their application,
            we strongly recommend that they upgrade all their log4j dependencies to the latest
            version (currently v2.20.0) - including log4j-api.</p>
      </section>

      <section><title>13 January 2021 - CVE-2021-23926 - XML External Entity (XXE) Processing in Apache XMLBeans versions prior to 3.0.0</title>
        <p>Description:<br/>
          When parsing XML files using XMLBeans 2.6.0 or below, the underlying parser
          created by XMLBeans could be susceptible to XML External Entity (XXE) attacks.</p>

        <p>This issue was fixed a few years ago but on review, we decided we should have a CVE
          to raise awareness of the issue.</p>

        <p>Mitigation:<br/>
          Affected users are advised to update to Apache XMLBeans 3.0.0 or above
          which fixes this vulnerability. XMLBeans 4.0.0 or above is preferable.</p>

        <p>References:
          <a href="https://en.wikipedia.org/wiki/XML_external_entity_attack">XML external entity attack</a>
        </p>
      </section>

      <section><title>20 October 2019 - CVE-2019-12415 - XML External Entity (XXE) Processing in Apache POI versions prior to 4.1.1</title>
        <p>Description:<br/>
          When using the tool XSSFExportToXml to convert user-provided Microsoft
          Excel documents, a specially crafted document can allow an attacker to
          read files from the local filesystem or from internal network resources
          via XML External Entity (XXE) Processing.</p>

        <p>Mitigation:<br/>
          Apache POI 4.1.0 and before: users who do not use the tool XSSFExportToXml
          are not affected. Affected users are advised to update to Apache POI 4.1.1
          which fixes this vulnerability.</p>

        <p>Credit:
          This issue was discovered by Artem Smotrakov from SAP</p>

        <p>References:
          <a href="https://en.wikipedia.org/wiki/XML_external_entity_attack">XML external entity attack</a>
        </p>
      </section>


      <!-- xmlbeans 3.1.0 release -->
      <section><title>26 March 2019 - XMLBeans 3.1.0 available</title>
      <p>The Apache POI team is pleased to announce the release of XMLBeans 3.1.0.
         Featured are a handful of bug fixes.</p>
      <p>The Apache POI project has unretired the XMLBeans codebase and is maintaining it as a sub-project,
         due to its importance in the poi-ooxml codebase.</p>
      <p>A summary of changes is available in the
        <a href="https://svn.apache.org/viewvc/xmlbeans/trunk/CHANGES.txt?view=markup">Release Notes</a>.
        People interested should also follow the <a href="site:mailinglists">POI dev list</a> to track progress.</p>
       <p>The XMLBeans <a href="https://issues.apache.org/jira/projects/XMLBEANS">JIRA project</a> has been reopened and feel free to open issues.</p>
       <p>POI 4.1.0 uses XMLBeans 3.1.0.</p>
       <p>XMLBeans requires Java 6 or newer since version 3.0.2.</p>
      </section>

      <section><title>11 January 2019 - Initial support for JDK 11</title>
        <p>We did some work to verify that compilation with Java 11 is working and
          that all unit-tests pass.
        </p>
        <p>See the details in the <a href="help/faq.html#faq-N102B0">FAQ entry</a>.</p>
      </section>
    </section>

    <section><title>Mission Statement</title>
      <p>
      The Apache POI Project's mission is to create and maintain Java APIs for manipulating various file formats
      based upon the Office Open XML standards (OOXML) and Microsoft's OLE 2 Compound Document format (OLE2).
      In short, you can read and write MS Excel files using Java.
      In addition, you can read and write MS Word and MS PowerPoint files using Java.  Apache POI is your Java Excel
      solution (for Excel 97-2008). We have a complete API for porting other OOXML and OLE2 formats and welcome others to participate.
      </p>
      <p>
      OLE2 files include most Microsoft Office files such as XLS, DOC, and PPT as well as MFC serialization API based file formats.
      The project provides APIs for the <a href="site:poifs">OLE2 Filesystem (POIFS)</a> and
      <a href="site:hpsf">OLE2 Document Properties (HPSF)</a>.
      </p>
      <p>
      Office OpenXML Format is the new standards based XML file format found in Microsoft Office 2007 and 2008.
      This includes XLSX, DOCX and PPTX. The project provides a low level API to support the Open Packaging Conventions
      using <a href="site:oxml4j">openxml4j</a>.
      </p>
      <p>
	For each MS Office application there exists a component module that attempts to provide a common high level Java api to both OLE2 and OOXML
	document formats. This is most developed for <a href="site:spreadsheet">Excel workbooks (SS=HSSF+XSSF)</a>.
	Work is progressing for <a href="site:document">Word documents (WP=HWPF+XWPF)</a> and
	<a href="site:slideshow">PowerPoint presentations (SL=HSLF+XSLF)</a>.
      </p>
      <p>
	The project has some support for <a href="site:hsmf">Outlook (HSMF)</a>. Microsoft opened the specifications
	to this format in October 2007. We would welcome contributions.
      </p>
      <p>
        There are also projects for
        <a href="site:diagram">Visio (HDGF and XDGF)</a>,
        <a href="site:hmef">TNEF (HMEF)</a>,
        and <a href="site:hpbf">Publisher (HPBF)</a>.
      </p>
      <p>
         As a general policy we collaborate as much as possible with other projects to
         provide this functionality.  Examples include: <a href="https://xml.apache.org/cocoon">Cocoon</a> for
         which there are serializers for HSSF;
         <a href="https://www.openoffice.org">Open Office.org</a> with whom we collaborate in documenting the
         XLS format; and <a href="https://tika.apache.org/">Tika</a> /
         <a href="https://lucene.apache.org">Lucene</a>,
         for which we provide format interpretors.  When practical, we donate
         components directly to those projects for POI-enabling them.
      </p>
      <section><title>Why should I use Apache POI?</title>
      <p>
	A major use of the Apache POI api is for <a href="text-extraction.html">Text Extraction</a> applications
	such as web spiders, index builders, and content management systems.
      </p>
        <p>
		So why should you use POIFS, HSSF or XSSF?
        </p>
        <p>
		You'd use POIFS if you had a document written in OLE 2 Compound Document Format, probably written using
		MFC, that you needed to read in Java. Alternatively, you'd use POIFS to write OLE 2 Compound Document Format
		if you needed to inter-operate with software running on the Windows platform. We are not just bragging when
		we say that POIFS is the most complete and correct implementation of this file format to date!
        </p>
        <p>
		You'd use HSSF if you needed to read or write an Excel file using Java (XLS). You'd use
        XSSF if you need to read or write an OOXML Excel file using Java (XLSX). The combined
        SS interface allows you to easily read and write all kinds of Excel files (XLS and XLSX)
        using Java. Additionally there is a specialized SXSSF implementation which allows to write
        very large Excel (XLSX) files in a memory optimized way.
        </p>
      </section>
      <section><title>Components</title>
	<p>
	  The Apache POI Project provides several component modules some of which may not be of interest to you.
	  Use the information on our <a href="site:components">Components</a> page to determine which
	  jar files to include in your classpath.
	</p>
      </section>
    </section>

    <section><title>Contributing</title>
      <p>
        So you'd like to contribute to the project? Great! We need enthusiastic,
        hard-working, talented folks to help us on the project, no matter your
        background. So if you're motivated, ready, and have the time: Download the
        source from the
        <a href="site:git">Git Repository</a>,
        <a href="site:howtobuild">build the code</a>, join the
        <a href="site:mailinglists">mailing lists</a>, and we'll be happy to
        help you get started on the project!
      </p>
      <p>
        Please read our <a href="site:guidelines">Contribution Guidelines</a>.
        When your contribution is ready submit a patch to our
        <a href="https://bz.apache.org/bugzilla/buglist.cgi?product=POI">Bug Database</a>.
      </p>
    </section>
  </body>
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    <legal>
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      <br />
      Apache POI, POI, Apache, the Apache feather logo, and the Apache
      POI project logo are trademarks of The Apache Software Foundation.
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