SiYuan: Missing authorization on refreshBacklink allows anonymous readers to trigger persistent server-side writes and unauthenticated resource amplification (publish mode)

CVE: This vulnerability corresponds to CVE-2026-72812. Summary The /api/ref/refreshBacklink endpoint is gated by CheckAuth only. Unlike its mutating siblings, it carries no CheckAdminRole, no CheckReadonly, and no inline reader-role guard so it falls through all three authorization mechanisms the...