{"id":18065,"date":"2026-09-08T00:30:42","date_gmt":"2026-09-07T16:30:42","guid":{"rendered":"https:\/\/www.54iter.cn\/?vuln=cve-2026-86431"},"modified":"2026-09-08T00:30:42","modified_gmt":"2026-09-07T16:30:42","slug":"cve-2026-86431","status":"publish","type":"vuln","link":"https:\/\/www.54iter.cn\/?vuln=cve-2026-86431","title":{"rendered":"CVE-2026-86431 [HIGH] &#8211; league\/commonmark (thephpleague\/commonmark) versions &gt;= 2.7.0 and &lt; 2.9.1 contain a cross-"},"content":{"rendered":"<p>league\/commonmark (thephpleague\/commonmark) versions &gt;= 2.7.0 and &lt; 2.9.1 contain a cross-site scripting vulnerability in the AttributesExtension. Prefixing an attribute name with a single U+000C form feed byte (e.g. {x0Conclick=&quot;alert(1)&quot;}) bypasses the AttributesHelper::filterAttributes() &#039;on*&#039; event-handler filter because PHP&#039;s trim() does not strip U+000C, causing the attribute to be written verbatim into the output where browsers parse it as a genuine event handler. The same prefix also defeats the allow_unsafe_links check, allowing javascript: URIs through href\/src attributes even when allow_unsafe_links is false. Exploitation requires processing untrusted Markdown with the AttributesExtension enabled; the injected script executes when the rendered HTML is viewed. Fixed in 2.9.1.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>league\/commonmark (thephpleague\/commonmark) versions &gt;= 2.7.0 and &lt; 2.9.1 contain a cross-site scripting vulnerability in the AttributesExtension. Prefixing an attribute name with a single U+000C form<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-18065","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/18065","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=18065"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=18065"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=18065"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}