{"id":29726,"date":"2026-09-27T00:31:33","date_gmt":"2026-09-26T16:31:33","guid":{"rendered":"https:\/\/www.54iter.cn\/?vuln=cve-2026-100646"},"modified":"2026-09-27T00:31:33","modified_gmt":"2026-09-26T16:31:33","slug":"cve-2026-100646","status":"publish","type":"vuln","link":"https:\/\/www.54iter.cn\/?vuln=cve-2026-100646","title":{"rendered":"CVE-2026-100646 [HIGH] &#8211; SiYuan is a self-hosted personal knowledge management system. In versions up to and includ"},"content":{"rendered":"<p>SiYuan is a self-hosted personal knowledge management system. In versions up to and including 3.8.3, the kernel&#8217;s authentication guards (CheckAuth in kernel\/model\/session.go and IsSessionOriginAllowed in kernel\/util\/net.go) fail open when the HTTP Origin header is absent, on the incorrect assumption that any browser-initiated cross-site request carries an Origin. Because browsers omit Origin on cross-site top-level GET navigations and no-cors GET subresource loads \u2014 and the session cookie is SameSite=Lax \u2014 a single cross-site GET issued from any attacker-controlled web page is granted RoleAdministrator, both on default installations with no access-authorization code and on password-protected instances with a live session. Combined with content-type sniffing on the \/api\/network\/proxy endpoint, which allows attacker-controlled HTML to be served under SiYuan&#8217;s own origin, this permits an unauthenticated remote attacker to execute arbitrary script in the SiYuan origin (http:\/\/127.0.0.1:6806), invoke administrator APIs, and exfiltrate the persistent kernel API token. This issue is fixed in version 3.8.4.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>SiYuan is a self-hosted personal knowledge management system. In versions up to and including 3.8.3, the kernel&#8217;s authentication guards (CheckAuth in kernel\/model\/session.go and IsSessionOriginAllowed<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-29726","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/29726","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=29726"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=29726"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=29726"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}