# CVE-2025-21609: SiYuan has an arbitrary file deletion vulnerability

> An attacker can delete arbitrary files on the server via a crafted payload in the history API endpoint of SiYuan Note.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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:** Yes
- **Published:** 3 Jan 2025
- **Updated:** 3 Jan 2025
- **Also known as:** GHSA-8fx8-pffw-w498, GO-2025-3362

## What is CVE-2025-21609?

CVE-2025-21609 is a high-severity path traversal vulnerability in B3log Siyuan, published on 3 Jan 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

SiYuan is self-hosted, open source personal knowledge management software. SiYuan Note version 3.1.18 has an arbitrary file deletion vulnerability. The vulnerability exists in the `POST /api/history/getDocHistoryContent` endpoint. An attacker can craft a payload to exploit this vulnerability, resulting in the deletion of arbitrary files on the server. Commit d9887aeec1b27073bec66299a9a4181dc42969f3 fixes this vulnerability and is expected to be available in version 3.1.19.

Weakness: CWE-552 (Files or Directories Accessible to External Parties), CWE-459 (Incomplete Cleanup)

## Which versions are affected by CVE-2025-21609?

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 | None |
| `github.com/siyuan-note/siyuan/kernel` | Go | All versions | None |

Products: B3log Siyuan.

## How do I fix CVE-2025-21609?

Upgrade to a fixed version.

## Is CVE-2025-21609 being exploited?

There is no known exploitation of CVE-2025-21609 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-2025-21609 and fix it if it is affected.

What it is: CVE-2025-21609 is a high-severity path traversal vulnerability in B3log Siyuan, published on 3 Jan 2025. 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-2025-21609 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; no fix listed
- github.com/siyuan-note/siyuan/kernel (Go): affected all versions; no fix listed

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-2025-21609/ (Markdown: https://insights.sbomify.com/CVE-2025-21609/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-21609
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-21609
- OSV: https://osv.dev/vulnerability/CVE-2025-21609

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-21609/
Summaries are generated and may contain mistakes; the official description above is the record.