TI-2025-33765 Aliases CVE-2025-53890 GHSA-8w3f-4r8f-pf53

pyLoad vulnerable to remote code execution through js2py onCaptchaResult

HIGH 82CWE-94Published 2025-07-14 · Updated 2025-07-15

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Code execution, Cross-site scripting
Confidentiality · integrity · availability: High · High · High
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-94 and CWE-79.

Summary

pyload is an open-source Download Manager written in pure Python. An unsafe JavaScript evaluation vulnerability in pyLoad’s CAPTCHA processing code allows unauthenticated remote attackers to execute arbitrary code in the client browser and potentially the backend server. Exploitation requires no user interaction or authentication and can result in session hijacking, credential theft, and full system remote code execution. Commit 909e5c97885237530d1264cfceb5555870eb9546, the patch for the issue, is included in version 0.5.0b3.dev89.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.01298 70th percentileScored 2026-11-07

Fix Fixed pyload (pyload): 0.5.0b3.dev89pyload-ng (PyPI): 0.20

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: Yes
Technical impact: Total

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	before 0.5.0b3.dev89	0.5.0b3.dev89	Patch available	CNA
—	pyload-ng (PyPI)	before 0.20	0.20	Patch available	GHSA-8w3f-4r8f-pf53

pyload Vendorpyload Affected before 0.5.0b3.dev89 Fixed in 0.5.0b3.dev89 Patch available CNA
pyload-ng (PyPI) Vendor— Affected before 0.20 Fixed in 0.20 Patch available GHSA-8w3f-4r8f-pf53

Remediation

Fix · CNA pyload (pyload) Fixed in 0.5.0b3.dev89
Fix · GHSA-8w3f-4r8f-pf53 pyload-ng (PyPI) Fixed in 0.20 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2025-53890
2026-10-03 Alias added: GHSA-8w3f-4r8f-pf53

References

Advisory 1

https://nvd.nist.gov/vuln/detail/CVE-2025-53890

Other 4

TI-2023-00282 Code Injection in pyload/pyload CVSS 3.1CRITICAL 9.8
TI-2025-34556 pyLoad CNL Blueprint is vulnerable to Path Traversal through `dlc_path` leading to Remote Code Execution (RCE) CVSS 3.1CRITICAL 9.8
TI-2023-00412 Excessive Attack Surface in pyload/pyload CVSS 3.1CRITICAL 9.8
TI-2026-27589 pyLoad has SSRF fix bypass via HTTP redirect CVSS 4.0CRITICAL 9.3
TI-2026-26332 pyLoad: Server-Side Request Forgery via Download Link Submission Enables Cloud Metadata Exfiltration CVSS 4.0CRITICAL 9.3
TI-2026-25907 pyload-ng: Authentication Bypass via Host Header Injection in ClickNLoad CVSS 4.0HIGH 8.8

See all 49 →

Sources

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