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<p><span>Hello everyone,</span></p>
<p><strong><span>TL;DR: PmWiki.org is temporarily offline, but we have backups, several options for restoring the website, and ways to access the content in the meantime. I am also available to help anyone who needs assistance with their PmWiki installation.</span></strong></p>
<h3><span>What happened?</span></h3>
<p><span>Last Wednesday, two critical vulnerabilities known as PHP2Shell were disclosed and patched in PHP. They can allow remote attackers to execute commands on a server without authentication, potentially gaining access to the server itself. The vulnerabilities affect PHP, not PmWiki specifically, and can impact any website running an affected PHP installation.</span></p>
<p><span>The recommended response is to upgrade to a fixed PHP version immediately or take the affected PHP installation offline until it can be secured.</span></p>
<p><span>At 18:00 Paris time (12:00 New York time), I contacted Pm about the situation. An hour later, I also sent a message to the PmWiki Users and Notify mailing lists, explaining the urgency and the need to address the vulnerabilities.</span></p>
<p><span>I have immediately upgraded the servers I manage and checked that the shared hosting plans I monitor were also up to date.</span></p>
<p><span>The situation on PmWiki.org is different because I manage the website itself, but not the underlying server, and I do not have the access needed to upgrade PHP or the operating system.</span></p>
<p><span>Pm responded quickly, and I understand that he has a lot on his plate at the moment. The server's operating system and PHP installations are quite old, so upgrading PHP may require a broader server upgrade, a reinstall, or a migration to a new server. On top of that, the hosting provider experienced an outage affecting its administration panel for several hours on Thursday and Friday, making it impossible to investigate the available options during that time.</span></p>
<p><span>In the meantime, Pm made a full backup of the PmWiki home directory.</span></p>
<h3><span>What I have done in the meantime</span></h3>
<p><span>There was also a separate issue: Subversion, our code repository, had stopped working a few days earlier, and I could not access it. Pm restarted the service, allowing me to commit the core changes I had pending.</span></p>
<p><span>I then released PmWiki 2.7.7 and, after Holger reported a bug, 2.7.8. These releases are unrelated to the PHP security vulnerabilities.</span></p>
<p><span>Given the security risk and the fact that I could not upgrade PHP myself, I notified Pm that I disabled PHP execution on the PmWiki.org website and replace the dynamic pages with a static HTML page. This is the page you currently see when visiting the site.</span></p>
<p><span>The static page provides access to:</span></p>
<ul data-spread="false">
<li>
<p><span>The latest PmWiki downloads, release notes, and change log.</span></p>
</li>
<li>
<p><span>All uploaded Cookbook recipes and skins.</span></p>
</li>
<li>
<p><span>The Internet Archive's Wayback Machine, with a direct link to the archived version of the corresponding page, where a recent cached copy may be available.</span></p>
</li>
</ul>
<p><span>The latest English documentation is also included in the PmWiki distribution archives, which can be downloaded from the static page.</span></p>
<h3><span>What is still available?</span></h3>
<p><span>Although the website is temporarily unavailable as a dynamic wiki, the following services and resources remain available:</span></p>
<ul data-spread="false">
<li>
<p><span>Subversion, which is normally working again.</span></p>
</li>
<li>
<p><span>The PmWiki mailing lists.</span></p>
</li>
<li>
<p><span>PmWiki core releases, Cookbook recipes, and skins, available for download from the static page.</span></p>
</li>
<li>
<p><span>Archived versions of individual pages through the Internet Archive.</span></p>
</li>
</ul>
<p><span>Both Pm and I have backups of the PmWiki home directory and installation, so we have copies of the content available while we work out the next steps.</span></p>
<h3><span>What are our options for restoring PmWiki.org?</span></h3>
<p><span>The first option is to upgrade the existing server, provided that this can be done safely and within a reasonable timeframe. Depending on the server's operating system and configuration, this might require a more extensive upgrade or migration.</span></p>
<p><span>I have also prepared an alternative: I installed a copy of the PmWiki.org content on one of my hosting plans, under a different domain name.</span></p>
<p><span>The copy mostly works, but moving from PHP 7.0 to PHP 8.4 is not straightforward. New PHP versions introduce changes that can cause older scripts to produce warnings or errors, or to stop working altogether. I continuously test and update the PmWiki core to support recent stable PHP versions, but individual Cookbook recipes, skins, and local configurations may also need attention.</span></p>
<p><span>To make this alternative viable, I would need to review the pages, particularly those in Cookbook, Skins, and Test, identify the problems, and update or disable the affected recipes and configurations as appropriate. If we decide to proceed with this option, I will ask for help identifying and testing the pages that need attention.</span></p>
<p><span>If we use the alternative installation, we could configure PmWiki.org to redirect visitors to the corresponding paths on the new domain. This could be a temporary arrangement while the original server is upgraded or migrated.</span></p>
<p><span>Once the original website is ready again, we could synchronize any changes made on the alternative installation back to the original one and redirect visitors back to PmWiki.org.</span></p>
<p><span>This would involve a considerable amount of work, so if Pm can upgrade the existing server in a reasonable timeframe, I would be happy to wait and help with the transition back to normal service. Otherwise, the alternative installation gives us another way forward.</span></p>
<p><span>For now, we are waiting for Pm to have time to assess the situation and decide how best to proceed. I am happy to help with either option.</span></p>
<h3><span>What about your own PmWiki installation?</span></h3>
<p><span>If you run PmWiki on your own server or hosting plan, please check your PHP installation as soon as possible.</span></p>
<p><span>The PHP releases that fix these vulnerabilities are:</span></p>
<ul data-spread="false">
<li>
<p><span>PHP 8.2.35</span></p>
</li>
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<p><span>PHP 8.3.36</span></p>
</li>
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<p><span>PHP 8.4.27</span></p>
</li>
<li>
<p><span>PHP 8.5.12</span></p>
</li>
</ul>
<p><span>Later releases in these branches also contain the fixes. If you are running an older PHP version, check whether your operating system or hosting provider has supplied a patched package. Some vendors backport security fixes to older versions, so the version number alone may not tell the whole story.</span></p>
<p><span>If your installation cannot be patched immediately, take the affected PHP service offline until you can secure it. Another possible interim measure is to use a web application firewall. Cloudflare has been reported as offering mitigation for this vulnerability, but such protection is not a substitute for applying the appropriate PHP security fixes. Using its proxy service also requires routing your DNS traffic through Cloudflare.</span></p>
<p><span>The vulnerabilities affect PHP itself, before the application code is processed. Consequently, changing PmWiki scripts or disabling a particular PmWiki feature is not a reliable way to fix them.</span></p>
<p><span>If an attacker exploits a vulnerable installation, the consequences may extend well beyond the wiki. Depending on the server's configuration and privileges, an attacker may be able to read page content, page histories, metadata, deleted pages, uploads, scripts, configuration files, and secrets stored on the server. They may also be able to modify the website, distribute malware, or access credentials that could be reused elsewhere.</span></p>
<p><span>This is why I strongly recommend upgrading to a patched PHP version, even if doing so exposes compatibility problems with older recipes or local customizations. Those problems can generally be investigated and addressed; leaving a server vulnerable to remote code execution is a much greater risk.</span></p>
<p><span>For more technical information, see the PHP security advisory and the relevant vendor guidance.</span></p>
<h3><span>How I can help</span></h3>
<p><span>If your PmWiki installation needs attention, please feel free to contact me.</span></p>
<p><span>I am available to help with upgrading older PmWiki installations, resolving PHP compatibility warnings and errors, updating Cookbook recipes and local customizations, and migrating wikis to a more recent PHP version or a different hosting plan.</span></p>
<p><span>If you have been putting off an upgrade because your wiki has accumulated years of customizations, we can work through the issues together and find a practical way to get it up to date and back online.</span></p>
<p><span>Thank you for your patience while we work through this situation, and thanks to Pm, to everyone who contacted me privately, and to everyone who helps maintain and support the PmWiki community.</span></p>
<p><span>Best regards,<br />Petko</span></p>
<p><br /></p>
<p id="reply-intro">On 21/10/2026 19:06, Petko Yotov wrote:</p>
<blockquote type="cite" style="padding: 0 0.4em; border-left: #1010ff 2px solid; margin: 0">
<div class="pre" style="margin: 0; padding: 0; font-family: monospace"><span style="font-family: arial, helvetica, sans-serif;">Hello everyone,</span><br /><br /><span style="font-family: arial, helvetica, sans-serif;">Today the PHP development team has announced two critical remote code execution (RCE) vulnerabilities affecting PHP. An attacker may be able to execute arbitrary code on a vulnerable server without authentication.</span><br /><br /><span style="font-family: arial, helvetica, sans-serif;">These vulnerabilities affect PHP itself, not just any particular web application, and not just PmWiki. PmWiki administrators and webmasters should check every server running PHP, including systems hosting multiple websites.</span><br /><br /><span style="font-family: arial, helvetica, sans-serif;">Vulnerabilities:</span><br /><span style="font-family: arial, helvetica, sans-serif;">* CVE-2026-109618: <a href="https://www.cve.org/CVERecord?id=CVE-2026-109618" target="_blank" rel="noopener noreferrer">https://www.cve.org/CVERecord?id=CVE-2026-109618</a></span><br /><span style="font-family: arial, helvetica, sans-serif;">* CVE-2026-109619: <a href="https://www.cve.org/CVERecord?id=CVE-2026-109619" target="_blank" rel="noopener noreferrer">https://www.cve.org/CVERecord?id=CVE-2026-109619</a></span><br /><br /><span style="font-family: arial, helvetica, sans-serif;">The vulnerabilities affect all PHP versions from PHP 5 onwards, including:</span><br /><span style="font-family: arial, helvetica, sans-serif;">* All PHP 5.x and 6.x versions</span><br /><span style="font-family: arial, helvetica, sans-serif;">* All PHP 7.x versions, including PHP 7.0</span><br /><span style="font-family: arial, helvetica, sans-serif;">* PHP 8.0 and 8.1, all versions</span><br /><span style="font-family: arial, helvetica, sans-serif;">* PHP 8.2 before 8.2.35</span><br /><span style="font-family: arial, helvetica, sans-serif;">* PHP 8.3 before 8.3.36</span><br /><span style="font-family: arial, helvetica, sans-serif;">* PHP 8.4 before 8.4.27</span><br /><span style="font-family: arial, helvetica, sans-serif;">* PHP 8.5 before 8.5.12</span><br /><br /><span style="font-family: arial, helvetica, sans-serif;">Official security announcement:</span><br /><span style="font-family: arial, helvetica, sans-serif;"> <a href="https://www.php.net/archive/2026.php" target="_blank" rel="noopener noreferrer">https://www.php.net/archive/2026.php</a></span><br /><br /><span style="font-family: arial, helvetica, sans-serif;">The PHP project has released fixes for PHP 8.2.35, 8.3.36, 8.4.27 and 8.5.12. Some vendors also provide backported fixes for older branches, including PHP 7.4, 8.0 and 8.1.</span><br /><br /><span style="font-family: arial, helvetica, sans-serif;">What you should do:</span><br /><br /><span style="font-family: arial, helvetica, sans-serif;">Check which PHP version your web server actually uses. Remember that the command-line PHP version may differ from the version used by Apache or PHP-FPM.</span><br /><br /><span style="font-family: arial, helvetica, sans-serif;">Update immediately to a fixed release, or install the security-patched package supplied by your Linux distribution or hosting provider.</span><br /><br /><span style="font-family: arial, helvetica, sans-serif;">If you are running an obsolete PHP branch such as PHP 7.0, do not assume it is safe. Upgrade to a currently supported PHP version, or confirm with your vendor that a security fix has been applied.</span><br /><br /><span style="font-family: arial, helvetica, sans-serif;">If you cannot patch an affected server immediately, consider isolating it from public access until it can be secured.</span><br /><br /><span style="font-family: arial, helvetica, sans-serif;">Further information in English:</span><br /><br /><span style="font-family: arial, helvetica, sans-serif;">PHP security announcement:</span><br /><span style="font-family: arial, helvetica, sans-serif;"> <a href="https://www.php.net/archive/2026.php#2026-10-21-2" target="_blank" rel="noopener noreferrer">https://www.php.net/archive/2026.php#2026-10-21-2</a></span><br /><br /><span style="font-family: arial, helvetica, sans-serif;">PHP advisory for CVE-2026-109618:</span><br /><span style="font-family: arial, helvetica, sans-serif;"> <a href="https://github.com/php/php-src/security/advisories/GHSA-w8hw-w9fx-j79w" target="_blank" rel="noopener noreferrer">https://github.com/php/php-src/security/advisories/GHSA-w8hw-w9fx-j79w</a></span><br /><br /><span style="font-family: arial, helvetica, sans-serif;">PHP advisory for CVE-2026-109619:</span><br /><span style="font-family: arial, helvetica, sans-serif;"> <a href="https://github.com/php/php-src/security/advisories/GHSA-6wmf-4rv5-p3rp" target="_blank" rel="noopener noreferrer">https://github.com/php/php-src/security/advisories/GHSA-6wmf-4rv5-p3rp</a></span><br /><br /><span style="font-family: arial, helvetica, sans-serif;">CERT-EU security advisory:</span><br /><span style="font-family: arial, helvetica, sans-serif;"> <a href="https://cert.europa.eu/publications/security-advisories/2026-018/" target="_blank" rel="noopener noreferrer">https://cert.europa.eu/publications/security-advisories/2026-018/</a></span><br /><br /><span style="font-family: arial, helvetica, sans-serif;">Please do not assume that a PmWiki installation is safe simply because it is up to date. These vulnerabilities are in the underlying PHP runtime, so updating PmWiki alone will not fix them.</span><br /><br /><span style="font-family: arial, helvetica, sans-serif;">Please check your servers and apply the appropriate security updates as soon as possible.</span><br /><br /><span style="font-family: arial, helvetica, sans-serif;">Petko</span></div>
</blockquote>
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