CVE-2026-30926 SiYuan Note publish service authorization bypass allows low-privilege users to modify notebook content
Low-privilege users can modify notebook content due to insufficient authorization checks in the publish service API.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-30926?
CVE-2026-30926 is a high-severity missing authorization vulnerability in B3log Siyuan, published on 9 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-30926?
3 open source packages ship an affected version, including github.com/siyuan-note/siyuan/kernel. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/siyuan-note/siyuan/kernel Go | All versions | None |
github.com/siyuan-note/siyuan/kernel Go | All versions to 0.0.0-20260304035530-d03ebdec8279 | None |
github.com/siyuan-note/siyuan/kernel Go | All versions to 0.0.0-20260304035530-d03ebdec8279 | None |
Products include B3log Siyuan.
How do I fix CVE-2026-30926?
Upgrade to a fixed version.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-30926 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-30926 exists.
Other vulnerabilities in B3log Siyuan
- CVE-2026-32938 SiYuan has an Arbitrary File Read in its Desktop Publish Service
- CVE-2026-33669 SiYuan has Arbitrary Document Reading within the Publishing Service
- CVE-2026-33670 SiYuan has directory traversal within its publishing service
- CVE-2026-32767 SiYuan: Authorization Bypass Allows Arbitrary SQL Execution via Search API
- CVE-2024-53504 SQL injection in n/a
Sources
Also known as GHSA-f9cq-v43p-v523, GO-2026-4658.