Skip to main content
CRITICAL

CVE-2025-53890

pyLoad vulnerable to remote code execution through js2py onCaptchaResult

CVSS v3

9.8

CRITICAL

EPSS Score

1.2 %

exploit probability, as of 2026-09-25

CISA KEV

No

known exploited

Exploitation

poc

SSVC status

Description

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,

Technical details

Published
2025-07-15
Last Modified
2026-04-15

Frequently asked questions

What is CVE-2025-53890?

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 CVE-2025-53890 actively exploited?

A proof-of-concept exploit exists for CVE-2025-53890, but active exploitation has not been confirmed at this time.

What is the CVSS score for CVE-2025-53890?

CVE-2025-53890 has a CVSS v3 base score of 9.8 (CRITICAL severity).

Is CVE-2025-53890 affecting your environment?

Use isMalicious to check if any of your IPs or domains are associated with this vulnerability's IOCs.

Check an IPSearch CVEsSIEM & TIP integrations

No credit card required · 500 free checks/month · Free API key

Other 2025 vulnerabilities worth triaging

Ranked by exploit probability (EPSS).

Back to CVE Database