How serious is CVE-2026-30926?

This vulnerability has a CVSS score of 7.1 out of 10, classified as HIGH severity. Proof-of-concept exploit code is publicly available, making this an active threat.

Is there exploit code available for CVE-2026-30926?

Yes, proof-of-concept exploit code for CVE-2026-30926 is publicly available on GitHub and security research platforms. This increases the risk of active exploitation.

Which products are affected by CVE-2026-30926?

CVE-2026-30926 affects b3log siyuan. Check the full CVE details for specific version information.

How do I fix CVE-2026-30926?

To remediate CVE-2026-30926, check for security patches from b3log. Apply all available updates and security patches. If no patch is available, implement recommended workarounds or security controls to mitigate the risk.

CVE-2026-30926

High

|7.1

Exploit Available

Plain English Summary

AI-powered analysis for quick understanding

This vulnerability allows low-privilege users to modify existing notebook content in the SiYuan knowledge management system, even though they should only have read-only access. It occurs because the system doesn't properly check user permissions, enabling these users to add new content to documents through a specific API.

Technical 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 Vector Analysis

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

Confidentiality ImpactLow

Integrity ImpactHigh

Availability ImpactNone

ScopeUnchanged

Vector String

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

Exploit Resources

Search for proof-of-concept code and exploit modules

GitHub Search Exploit-DB Nuclei Templates Metasploit Vulners

Official References

NIST NVD

Est. Bounty

$1,211($1K-$5K)

Vendor Response

Grade APatched in 3 days

Quick Information

Published

Mar 10, 2026

28 days ago

Last Modified

Mar 13, 2026

25 days ago

Vendor

b3log

Product

siyuan

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