TI-2026-25907 Aliases CVE-2026-33511

pyload-ng: Authentication Bypass via Host Header Injection in ClickNLoad

HIGH 77CWE-639Published 2026-03-24 · Updated 2026-03-25

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Attack requirements: None
Impact type: Security bypass
Confidentiality · integrity · availability: Low · High · Low
Fix status: Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-639.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00438 38th percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by NVD

Fix Fixed pyload (pyload): 0.5.0b3.dev97

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
pyload	pyload	0.4.20 to before 0.5.0b3.dev97	0.5.0b3.dev97	Patch available	CNA

pyload Vendorpyload Affected 0.4.20 to before 0.5.0b3.dev97 Fixed in 0.5.0b3.dev97 Patch available CNA

CPE configurations NVD · 2

CPE	Versions	Role	Vendor
cpe:2.3:a:pyload:pyload::::::::	up to 0.4.20	Vulnerable	pyload
cpe:2.3:a:pyload-ng_project:pyload-ng::::::python::*	0.5.0a5.dev528 to before 0.5.0b3.dev97	Vulnerable	Pyload-ng Project

cpe:2.3:a:pyload:pyload:*:*:*:*:*:*:*:* Versions up to 0.4.20 Vulnerable ·pyload
cpe:2.3:a:pyload-ng_project:pyload-ng:*:*:*:*:*:python:*:* Versions 0.5.0a5.dev528 to before 0.5.0b3.dev97 Vulnerable ·Pyload-ng Project

Remediation

Fix · CNA pyload (pyload) Fixed in 0.5.0b3.dev97

Timeline

2026-10-02 Threatist record created from CVE-2026-33511
2026-10-21 EPSS moved to the 50th–90th percentile
2026-10-25 EPSS moved to the below the 50th percentile

References

Exploit 1

https://github.com/pyload/pyload/security/advisories/GHSA-g5j2-gxqh-x7pw

TI-2023-00282 Code Injection in pyload/pyload CVSS 3.1CRITICAL 9.8
TI-2023-00412 Excessive Attack Surface in pyload/pyload CVSS 3.1CRITICAL 9.8
TI-2026-26332 pyLoad: Server-Side Request Forgery via Download Link Submission Enables Cloud Metadata Exfiltration CVSS 4.0CRITICAL 9.3
TI-2024-32088 pyLoad vulnerable to remote code execution by download to /.pyload/scripts using /flashgot API CVSS 3.1CRITICAL 9.1
TI-2026-29761 pyLoad has Stale Session Privilege After Role/Permission Change (Privilege Revocation Bypass) CVSS 3.1HIGH 8.8
TI-2026-25905 pyload-ng: SETTINGS Permission Users Can Achieve Remote Code Execution via Unrestricted Reconnect Script Configuration CVSS 3.1HIGH 8.8

See all 22 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences