# CVE-2026-40318: SiYuan: Publish Reader Path Traversal Delete via `removeUnusedAttributeView`

> Attackers can delete arbitrary JSON files on the server via path traversal in the removeUnusedAttributeView API endpoint.

- **Severity:** High 8.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 16 Apr 2026
- **Updated:** 18 Apr 2026
- **Also known as:** GHSA-vw86-c94w-v3x4, GO-2026-5679

## What is CVE-2026-40318?

CVE-2026-40318 is a high-severity path traversal vulnerability in B3log Siyuan, published on 16 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

SiYuan is an open-source personal knowledge management system. In versions 3.6.3 and prior, the /api/av/removeUnusedAttributeView endpoint constructs a filesystem path using the user-controlled id parameter without validation or path boundary enforcement. An attacker can inject path traversal sequences such as ../ into the id value to escape the intended directory and delete arbitrary .json files on the server, including global configuration files and workspace metadata. This issue has been fixed in version 3.6.4.

Weakness: CWE-24 (Path Traversal: '../filedir')

## Which versions are affected by CVE-2026-40318?

3 open source packages ship an affected version, including github.com/siyuan-note/siyuan/kernel. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/siyuan-note/siyuan/kernel` | Go | All versions | None |
| `github.com/siyuan-note/siyuan/kernel` | Go | All versions | 3.6.40.0.0-20260407035653-2f416e5253f1 |
| `github.com/siyuan-note/siyuan/kernel` | Go | All versions | 3.6.40.0.0-20260407035653-2f416e5253f1 |

Products: B3log Siyuan.

## How do I fix CVE-2026-40318?

Upgrade github.com/siyuan-note/siyuan/kernel to 3.6.40.0.0-20260407035653-2f416e5253f1 or later.

## Is CVE-2026-40318 being exploited?

There is no known exploitation of CVE-2026-40318 in the wild and no public exploit code.

## Other vulnerabilities in B3log Siyuan

- [CVE-2026-32938](https://insights.sbomify.com/CVE-2026-32938/): SiYuan has an Arbitrary File Read in its Desktop Publish Service (critical 9.9)
- [CVE-2026-33669](https://insights.sbomify.com/CVE-2026-33669/): SiYuan has Arbitrary Document Reading within the Publishing Service (critical 9.8)
- [CVE-2026-33670](https://insights.sbomify.com/CVE-2026-33670/): SiYuan has directory traversal within its publishing service (critical 9.8)
- [CVE-2026-32767](https://insights.sbomify.com/CVE-2026-32767/): SiYuan: Authorization Bypass Allows Arbitrary SQL Execution via Search API (critical 9.8)
- [CVE-2024-53504](https://insights.sbomify.com/CVE-2024-53504/): SQL injection in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-40318 and fix it if it is affected.

What it is: CVE-2026-40318 is a high-severity path traversal vulnerability in B3log Siyuan, published on 16 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-40318 in the wild and no public exploit code.

Affected packages and fixed versions:
- github.com/siyuan-note/siyuan/kernel (Go): affected all versions; no fix listed
- github.com/siyuan-note/siyuan/kernel (Go): affected all versions; fixed in 3.6.40.0.0-20260407035653-2f416e5253f1
- github.com/siyuan-note/siyuan/kernel (Go): affected all versions; fixed in 3.6.40.0.0-20260407035653-2f416e5253f1

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-2026-40318/ (Markdown: https://insights.sbomify.com/CVE-2026-40318/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-40318
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-40318
- OSV: https://osv.dev/vulnerability/CVE-2026-40318

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-40318/
Summaries are generated and may contain mistakes; the official description above is the record.