# CVE-2026-105205: SiYuan before 3.8.5 Information Disclosure via /api/block/getDocInfo and getDocsInfo

> Attackers can leak hidden block IDs and reference counts from protected documents via API queries, exposing metadata in SiYuan.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 4 Oct 2026
- **Updated:** 5 Oct 2026
- **Also known as:** GHSA-9fqr-vwrf-9xx3, GHSA-v758-8w88-pfr2

## What is CVE-2026-105205?

CVE-2026-105205 is a medium-severity vulnerability in siyuan-note siyuan, published on 4 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

SiYuan before 3.8.5 contains an information disclosure vulnerability that allows publish-mode readers to learn backlink block IDs and reference counts from password-protected and publish-disabled documents by querying a published document. Attackers can send POST requests to /api/block/getDocInfo or getDocsInfo for a published document ID to obtain refIDs and refCount of hidden referencing blocks, bypassing the publish confidentiality boundary.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2026-105205?


## How do I fix CVE-2026-105205?

No fix has been published for CVE-2026-105205 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-105205 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-105205 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-105205 and fix it if it is affected.

What it is: CVE-2026-105205 is a medium-severity vulnerability in siyuan-note siyuan, published on 4 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-105205 exists.

Affected product: siyuan-note siyuan. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-105205/ (Markdown: https://insights.sbomify.com/CVE-2026-105205/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-105205
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-105205
- OSV: https://osv.dev/vulnerability/CVE-2026-105205

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-105205/
Summaries are generated and may contain mistakes; the official description above is the record.