Is CVE-2026-105205 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-105205 being exploited in the wild.

How severe is CVE-2026-105205?

Medium severity, with a CVSS score of 5.3, published 4 October 2026.

Is there a fix for CVE-2026-105205?

Yes: fixed in 3.8.5. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-105205 attacked?

It is attacked over the network.

Am I affected by CVE-2026-105205?

Check whether you run SiYuan at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-105205: SiYuan information disclosure in block API endpoints

CVE-2026-105205 · Severity: medium · CVSS 5.3 · Published 2026-10-04

SiYuan is a note-taking and knowledge management application that lets users publish documents for sharing. An information disclosure flaw allows anyone reading a published document to learn the existence and internal block IDs of other documents that reference it, even when those documents are password-protected or publish-disabled. An attacker can use API calls to extract this hidden metadata, circumventing access controls meant to keep sensitive documents confidential.

Technologies: SiYuan. Vendors: SiYuan.

Quick answers

Is CVE-2026-105205 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-105205 being exploited in the wild.
How severe is CVE-2026-105205?: Medium severity, with a CVSS score of 5.3, published 4 October 2026.
Which products and versions are affected?: SiYuan before 3.8.5.
Is there a fix for CVE-2026-105205?: Yes: fixed in 3.8.5. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-105205 attacked?: It is attacked over the network.
Am I affected by CVE-2026-105205?: Check whether you run SiYuan at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

Fixed in: 3.8.5

Technical details

The vulnerability exists in the /api/block/getDocInfo and /api/block/getDocsInfo endpoints, which lack proper publish-access filtering. These handlers return refIDs (block identifiers of referencing blocks) and refCount without checking whether the referencing blocks belong to password-protected or publish-disabled documents. A publish-mode reader can query any published document and receive backlink metadata from hidden documents via POST requests, as the FilterBlockInfoByPublishAccess filter only clears this data when the requested document itself is inaccessible—a condition never met for intentionally published documents.

Affected products

SiYuan SiYuan before 3.8.5

Timeline

2026-10-04: disclosed
2026-09-20: advisory

References

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