CVE-2026-30926
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.31%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.1 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N
- EPSS
- 0.31% probability · 24th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-284, CWE-862
- Affected
- b3log/siyuan
- Source
- security-advisories@github.com
References
- https://github.com/siyuan-note/siyuan/security/advisories/GHSA-f9cq-v43p-v523Exploit, Vendor Advisory
- https://github.com/siyuan-note/siyuan/security/advisories/GHSA-f9cq-v43p-v523Exploit, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.