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High severity7.5OSV Advisory· Published Jul 22, 2025· Updated Apr 15, 2026

CVE-2025-54140

CVE-2025-54140

Description

pyLoad is a free and open-source Download Manager written in pure Python. In version 0.5.0b3.dev89, an authenticated path traversal vulnerability exists in the /json/upload endpoint of pyLoad. By manipulating the filename of an uploaded file, an attacker can traverse out of the intended upload directory, allowing them to write arbitrary files to any location on the system accessible to the pyLoad process. This may lead to: Remote Code Execution (RCE), local privilege escalation, system-wide compromise, persistence, and backdoors. This is fixed in version 0.5.0b3.dev90.

Affected packages

Versions sourced from the GitHub Security Advisory.

PackageAffected versionsPatched versions
pyload-ngPyPI
>= 0.5.0b3.dev89, < 0.5.0b3.dev900.5.0b3.dev90

Affected products

1

Patches

1
fc4b136e9c4e

Fix uncontrolled data used in path expression used in add_package() (#4589)

https://github.com/pyload/pyloadZeroday BYTEJul 18, 2025via ghsa
commit
1 file changed · +3 −1
  • src/pyload/webui/app/blueprints/json_blueprint.py+3 −1 modified
    @@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 
 import os
+from werkzeug.utils import secure_filename
 
 import flask
 from flask.json import jsonify
@@ -151,8 +152,9 @@ def add_package():
             if not package_name or package_name == "New Package":
                 package_name = file.filename
 
+            safe_filename = secure_filename(file.filename)
             file_path = os.path.join(
-                api.get_config_value("general", "storage_folder"), "tmp_" + file.filename
+                api.get_config_value("general", "storage_folder"), "tmp_" + safe_filename
             )
             file.save(file_path)
             links.insert(0, file_path)

Vulnerability mechanics

Synthesis attempt was rejected by the grounding validator. Re-run pending.

References

5

News mentions

0

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