# CVE-2026-116167: SiYuan 2.9.0 before 3.8.7 XSS via check-auth to Parameter


- **Severity:** High 7.6 (`CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 25 Oct 2026
- **Updated:** 26 Oct 2026
- **Also known as:** GHSA-fmj3-xc2f-6w4w, GHSA-jvrf-pm5c-jgr4

## What is CVE-2026-116167?

CVE-2026-116167 is a high-severity vulnerability in siyuan-note siyuan, published on 25 Oct 2026. 

### Official description

SiYuan from 2.9.0 before 3.8.7 contains a cross-site scripting vulnerability in the unauthenticated /check-auth page that assigns the to parameter to window.location.href without scheme validation. Attackers can send a crafted link with a javascript: URI that executes after victim login, invoking kernel APIs to read or modify workspace content and settings.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-116167?


## How do I fix CVE-2026-116167?

No fix has been published for CVE-2026-116167 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-116167 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-116167 exists.

Public exploit code:

- SiYuan 2.9.0-3.8.6 - Unauthenticated XSS via check-auth "to" Parameter (nuclei): http/cves/2026/CVE-2026-116167.yaml

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-116167 and fix it if it is affected.

What it is: CVE-2026-116167 is a high-severity vulnerability in siyuan-note siyuan, published on 25 Oct 2026. 
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-116167 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-2026-116167/ (Markdown: https://insights.sbomify.com/CVE-2026-116167/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-116167
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-116167
- OSV: https://osv.dev/vulnerability/CVE-2026-116167

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-116167/
Summaries are generated and may contain mistakes; the official description above is the record.