CVE-2026-72811: SiYuan: SQL injection in backlink/mention search via unescaped stored and client input (publish mode): first-order (client keyword) and second-order (stored document title) breakout on read-write handle

Severity: Critical

CVSS Score: 10

SiYuan versions <= v3.7.2 contain a SQL injection vulnerability in the backlink/mention search query (kernel/model/backlink.go), which concatenates stored block metadata (title, name, alias, anchor text) and the client-supplied keyword into a SQL MATCH/search statement while escaping only the double-quote character and not the single quote. A single quote in the client keyword (first-order, reachable by an anonymous or RoleReader user on the publish surface) or in stored document metadata (second-order) breaks out of the string literal. Because the query runs on the main read-write siyuan.db handle via a statement-stacking-capable driver, an attacker can execute arbitrary SQL, enabling cross-notebook read and write. Fixed in v3.7.4.