CVE-2026-33511 pyload-ng: Authentication Bypass via Host Header Injection in ClickNLoad
Remote attackers can bypass authentication via Host header spoofing to inject downloads, write files, and execute JavaScript in pyLoad.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-33511?
CVE-2026-33511 is a high-severity authentication bypass vulnerability in pyload, published on 24 Mar 2026. 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 Python. From version 0.4.20 to before version 0.5.0b3.dev97, the local_check decorator in pyLoad's ClickNLoad feature can be bypassed by any remote attacker through HTTP Host header spoofing. This allows unauthenticated remote users to access localhost-restricted endpoints, enabling them to inject arbitrary downloads, write files to the storage directory, and execute JavaScript code. This issue has been patched in version 0.5.0b3.dev97.
Weakness: CWE-639
Which versions are affected by CVE-2026-33511?
It affects 2 products.
Products include Pyload-Ng Project Pyload-Ng, Pyload Pyload.
How do I fix CVE-2026-33511?
No fix has been published for CVE-2026-33511 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-33511 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33511 exists.
Other vulnerabilities in pyload
- CVE-2025-54802 pyLoad CNL Blueprint is vulnerable to Path Traversal through `dlc_path` leading to Remote Code Execution (RCE)
- CVE-2024-22416 Cross-Site Request Forgery on any API call in pyLoad may lead to admin privilege escalation
- CVE-2023-0488 Cross-site Scripting (XSS) - Stored in pyload/pyload
- CVE-2026-35459 pyLoad has SSRF fix bypass via HTTP redirect
- CVE-2026-35463 pyLoad has Improper Neutralization of Special Elements used in an OS Command
Sources
Also known as GHSA-g5j2-gxqh-x7pw.