Vulnerability · Published Aug 18, 2026 · Assigned by VulnCheck

CVE-2026-74904SiYuan before v3.7.4 Missing Authorization via block API

High 7.5

In plain English

A high-severity missing authorization in siyuan from siyuan-note. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 39% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.4%top 60.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

SiYuan before v3.7.4 is missing authorization checks in 17 block metadata/content endpoints in kernel/api/block.go (including getRefText, checkBlockExist, and getBlockBreadcrumb). These handlers are gated only by basic authentication (model.CheckAuth) and lack publish-access filtering, allowing anonymous publish-mode readers to disclose private block content-derived text, structural metadata, and existence information for arbitrary block IDs across the workspace.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Go	github.com/siyuan-note/siyuan/kernel	0.0.0-20260804015139-bd067a4fe9b2	GHSA-4vpg-gwqq-w44c
Go	github.com/siyuan-note/siyuan/kernel	0.0.0-20260804015139-bd067a4fe9b2	GO-2026-6654

Affected products (as reported)

Vendor	Product	Versions
siyuan-note	siyuan	0 – before 3.7.4

Weakness: CWE-862 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

References

GitHub Security Advisory (GHSA-4vpg-gwqq-w44c) vendor-advisory
VulnCheck Advisory: SiYuan before v3.7.4 Missing Authorization via block API third-party-advisory