# CVE-2026-58166: OpenBMB ChatDev - Unauthenticated Path Traversal in Upload Handler Allows Arbitrary File Write and Delete

> Unauthenticated attackers can write or delete arbitrary files via path traversal in the upload handler, potentially leading to remote code execution.

- **Severity:** High 8.8 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/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:** No
- **Published:** 30 Jun 2026
- **Updated:** 14 Jul 2026
- **Also known as:** GHSA-hh77-fhmp-pqfv

## What is CVE-2026-58166?

CVE-2026-58166 is a high-severity path traversal vulnerability in OpenBMB ChatDev, published on 30 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

OpenBMB ChatDev through 2.2.0, fixed in commit 4fd4da6, contains a path traversal vulnerability that allows unauthenticated remote attackers to write or delete arbitrary files by supplying a malicious multipart filename in the file upload endpoint. Attackers can send a crafted filename containing path traversal sequences or an absolute path to the POST uploads session endpoint, which constructs the destination path without sanitization in save_upload_file, causing file write and cleanup operations to target attacker-chosen paths on the server filesystem.

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

## Which versions are affected by CVE-2026-58166?


## How do I fix CVE-2026-58166?

No fix has been published for CVE-2026-58166 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-58166 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-58166 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-58166 and fix it if it is affected.

What it is: CVE-2026-58166 is a high-severity path traversal vulnerability in OpenBMB ChatDev, published on 30 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-58166 exists.

Affected product: OpenBMB ChatDev. 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-2026-58166/ (Markdown: https://insights.sbomify.com/CVE-2026-58166/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-58166
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-58166
- OSV: https://osv.dev/vulnerability/CVE-2026-58166

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-58166/
Summaries are generated and may contain mistakes; the official description above is the record.