CVE-2026-100646High· 8.1▾ MidnightPoC availableSiYuan is a self-hosted personal knowledge management system. In versions up to and including 3.8.3, the kernel's authentication guards (CheckAuth in kernel/model/session.go and IsSessionOriginAllowed in kernel/util/net.go) fail open whe…
▾ Midnight zone — Critical, or high with PoC / in-the-wild
impact 44.6 · likelihood 0 · exploitation 12
A public proof-of-concept already exists for this vulnerability — see Exploit availability below.
Stakeholder-Specific Vulnerability Categorization from CISA's ADP record at CVE.org: whether exploitation is observed, whether an attack can be automated, and how much of the system is at stake.
Exploit-prediction probability, daily snapshots since Sep 28.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
0.2%
Last analysed / modified upstream
Exploit / PoC code exists
0.2% → 0.2%
SiYuan is a self-hosted personal knowledge management system. In versions up to and including 3.8.3, the kernel'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 — and the session cookie is SameSite=Lax — 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'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.
Refer to the linked advisories for vendor-supplied fixes and affected version ranges.
Field changes observed since this record was first indexed.
Connected by shared product, vendor, weakness, or advisory.
CVE-2026-100642High· 7.6SiYuan versions from v2.1.0 before v3.8.4 contain a cross-site request forgery vulnerability in the CheckAuth lock-screen pass-through branch that grants administrator access to loopback requests without validating Origin headers
CVE-2026-109310Medium· 6.5SiYuan v3.1.12 before v3.8.6 fails to restrict the Sprig template function map in the /api/icon/getDynamicIcon content parameter, allowing resource exhaustion
CVE-2026-75917High· 8.6SiYuan before v3.7.4 contains a cross-site scripting vulnerability in the file-tree picker's hover-tooltip generation (app/src/util/pathName.ts, getLeaf()/movePathTo()) used by the 'move/link to' path-selection dialogs, where document me…
CVE-2026-75916High· 8.6SiYuan through 3.7.3 contains a cross-site scripting vulnerability in the '((' block-reference autocomplete hint popup
CVE-2026-105205Medium· 5.3SiYuan before 3.8.5 contains an information disclosure vulnerability that allows publish-mode readers to learn backlink block IDs and reference counts from password-protected and publish-disabled documents by querying a published documen…
CVE-2026-103763Medium· 5.8SiYuan before v3.8.5 contains an information disclosure vulnerability that allows read-only publish readers to learn metadata of publish-excluded documents through the getNotebookInfo endpoint