CVE-2026-30926

SiYuan Note publish service authorization bypass allows low-privilege users to modify notebook content

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

siyuan-note · siyuan

CVSS v3.1 GITHUB

7.1 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N

EPSS

0.36% chance of exploitation in the next 30 days, 28th percentile

Published

2026-03-09

Updated

2026-03-10

Proof-of-concept exploits (1)

• advisories/GHSA-f9cq-v43p-v523

Security advisories

• siyuan-note/siyuan/security/advisories/GHSA-f9cq-v43p-v523

References

• CVE Record
• NVD entry