# CVE-2026-68586: SiYuan before v3.7.3 Content Disclosure via getBacklinkDoc

> Attackers can bypass publish filters to read restricted document content via unfiltered API endpoints in SiYuan.

- **Severity:** Critical 9.2 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/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:** Yes
- **Published:** 3 Aug 2026
- **Updated:** 14 Aug 2026
- **Also known as:** GHSA-36v8-mpjm-8j5r, GO-2026-6379

## What is CVE-2026-68586?

CVE-2026-68586 is a critical missing authorization vulnerability in siyuan-note siyuan, published on 3 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

SiYuan before v3.7.3 fails to apply publish-access filters to the getBacklinkDoc and getBackmentionDoc content endpoints (/api/ref/getBacklinkDoc and /api/ref/getBackmentionDoc). While the corresponding backlink list endpoints filter publish-forbidden documents, the content endpoints (gated only by CheckAuth) do not. A publish-mode reader — including an anonymous reader when publish Basic Auth is disabled — can call these endpoints directly with a publish-forbidden document's ID to retrieve its rendered DOM content and to determine whether the document references a given block (a reference-existence oracle).

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2026-68586?

3 open source packages ship an affected version, including github.com/siyuan-note/siyuan/kernel.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/siyuan-note/siyuan/kernel` | Go | All versions | 0.0.0-20260721014413-f45749a7ef6e |
| `github.com/siyuan-note/siyuan/kernel` | Go | All versions | 0.0.0-20260721014413-f45749a7ef6e |
| `github.com/siyuan-note/siyuan/kernel` | Go | All versions | 0.0.0-20260721014413-f45749a7ef6e |

## How do I fix CVE-2026-68586?

Upgrade github.com/siyuan-note/siyuan/kernel to 0.0.0-20260721014413-f45749a7ef6e or later.

## Is CVE-2026-68586 being exploited?

There is no known exploitation of CVE-2026-68586 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-68586 and fix it if it is affected.

What it is: CVE-2026-68586 is a critical missing authorization vulnerability in siyuan-note siyuan, published on 3 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-68586 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/siyuan-note/siyuan/kernel (Go): affected all versions; fixed in 0.0.0-20260721014413-f45749a7ef6e
- github.com/siyuan-note/siyuan/kernel (Go): affected all versions; fixed in 0.0.0-20260721014413-f45749a7ef6e
- github.com/siyuan-note/siyuan/kernel (Go): affected all versions; fixed in 0.0.0-20260721014413-f45749a7ef6e

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-2026-68586/ (Markdown: https://insights.sbomify.com/CVE-2026-68586/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-68586
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-68586
- OSV: https://osv.dev/vulnerability/CVE-2026-68586

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-68586/
Summaries are generated and may contain mistakes; the official description above is the record.