CVE-2025-54140 pyLoad has Path Traversal Vulnerability in json/upload Endpoint that allows Arbitrary File Write
Authenticated attackers can write arbitrary files via path traversal in pyLoad, potentially leading to remote code execution and privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-54140?
CVE-2025-54140 is a high-severity path traversal vulnerability in pyload, published on 22 Jul 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-22
Which versions are affected by CVE-2025-54140?
3 open source packages ship an affected version, including pyload-ng.
| Package | Affected | Fixed in |
|---|---|---|
pyload-ng PyPI | From 0.5.0b3.dev89 | 0.5.0b3.dev90 |
pyload-ng PyPI | From 0.5.0b3.dev89 | 0.5.0b3.dev90 |
pyload-ng PyPI | From 0.5.0b3.dev89 | 0.5.0b3.dev90 |
How do I fix CVE-2025-54140?
Upgrade pyload-ng to 0.5.0b3.dev90 or later.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2025-54140 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-54140 exists.
Sources
Also known as GHSA-xqpg-92fq-grfg, PYSEC-2026-1823.