# CVE-2026-77086: SiYuan before v3.7.4 Path Traversal via packageName

> Authenticated administrators can exploit path traversal in SiYuan to write arbitrary files or delete directories, potentially leading to code execution.

- **Severity:** Critical 9.4 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 21 Aug 2026
- **Updated:** 1 Oct 2026
- **Also known as:** GHSA-w7g2-952j-gmgr

## What is CVE-2026-77086?

CVE-2026-77086 is a critical path traversal vulnerability in siyuan-note siyuan, published on 21 Aug 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

SiYuan before v3.7.4 fails to validate the packageName parameter in Bazaar install and uninstall endpoints, allowing authenticated administrators to perform path traversal via directory traversal sequences. Attackers with admin access can write arbitrary files to any location via install operations or recursively delete directories via uninstall operations by supplying crafted packageName values.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-77086?


## How do I fix CVE-2026-77086?

No fix has been published for CVE-2026-77086 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-77086 being exploited?

There is no known exploitation of CVE-2026-77086 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-77086 and fix it if it is affected.

What it is: CVE-2026-77086 is a critical path traversal vulnerability in siyuan-note siyuan, published on 21 Aug 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-77086 in the wild and no public exploit code.

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-2026-77086/ (Markdown: https://insights.sbomify.com/CVE-2026-77086/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-77086
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-77086
- OSV: https://osv.dev/vulnerability/CVE-2026-77086

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-77086/
Summaries are generated and may contain mistakes; the official description above is the record.