CVE-2025-57751 Denial-of-Service attack in pyLoad CNL Blueprint using dukpy.evaljs
Attackers can cause a denial of service in pyLoad by sending malicious input to the jk parameter, leading to high CPU usage and unresponsiveness.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-57751?
CVE-2025-57751 is a high-severity denial of service vulnerability in pyload, published on 21 Aug 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
pyLoad is the free and open-source Download Manager written in pure Python. The jk parameter is received in pyLoad CNL Blueprint. Due to the lack of jk parameter verification, the jk parameter input by the user is directly determined as dykpy.evaljs(), resulting in the server CPU being fully occupied and the web-ui becoming unresponsive. This vulnerability is fixed in 0.5.0b3.dev92.
Weakness: CWE-400
Which versions are affected by CVE-2025-57751?
3 open source packages ship an affected version, including pyload-ng.
| Package | Affected | Fixed in |
|---|---|---|
pyload-ng PyPI | All versions | 0.5.0b3.dev92 |
pyload-ng PyPI | All versions | 0.5.0b3.dev92 |
pyload-ng PyPI | All versions | 0.5.0b3.dev92 |
How do I fix CVE-2025-57751?
Upgrade pyload-ng to 0.5.0b3.dev92 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-57751 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-57751 exists.
Sources
Also known as GHSA-9gjj-6gj7-c4wj, PYSEC-2026-1815.