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CVE-2026-33511

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

Published: Mar 24, 2026Updated: Mar 26, 2026 Sources: CVE List NVDCWE-639
NVD MITRE
9.8CVSSCRITICAL
EPSS Score
0.4%
Top 66.4%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Workaround Only

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.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:HI:HA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:HAvailability
High
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Weaknesses

CWE-639

Affected Products

pyloadpyload
On-prem
Consumer Software / file-utility
pyload-ngpyload-ng project
On-prem
Consumer Software / file-utility
pyloadoss-projectConsumer Softwareaka pyload/pyload
pyload-ng projectoss-projectConsumer Softwareaka pyload-ng

Attack Graph

Products CVE Techniques Tactics

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Exploitability

Workaround Available

MITRE ATT&CK

1 technique
Initial Access
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References

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

Timeline

Published
Mar 24, 2026
Last Updated
Mar 26, 2026

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