What’s Vulnerable › Vulnerabilities

CVE-2026-30926: SiYuan Note publish service authorization bypass allows low-privilege users to modify notebook content

• Severity: high (CVSS 7.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-03-10 · updated 2026-06-17
• Weakness: CWE-284

Description

SiYuan is a personal knowledge management system. Prior to 3.5.10, a privilege escalation vulnerability exists in the publish service of SiYuan Note that allows low-privilege publish accounts (RoleReader) to modify notebook content via the /api/block/appendHeadingChildren API endpoint. The endpoint requires only the model.CheckAuth role, which accepts RoleReader sessions, but it does not enforce stricter checks, such as CheckAdminRole or CheckReadonly. This allows remote authenticated publish users with read-only privileges to append new blocks to existing documents, compromising the integrity of stored notes.

Affected products

• siyuan-note siyuan: before 3.5.10 — fixed in 3.5.10

How to fix

Upgrade to a fixed version: siyuan-note siyuan 3.5.10. Check the vendor advisory for mitigations.

References

• https://github.com/siyuan-note/siyuan/security/advisories/GHSA-f9cq-v43p-v523
• https://github.com/siyuan-note/siyuan/security/advisories/GHSA-f9cq-v43p-v523

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