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

> Attackers can inject arbitrary code via unsanitized parameters in pyLoad's web interface, leading to code execution or XSS.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 9 Oct 2025
- **Updated:** 10 Oct 2025
- **Also known as:** GHSA-cjjf-27cc-pvmv, PYSEC-2026-1816

## What is CVE-2025-61773?

CVE-2025-61773 is a high-severity code injection vulnerability in pyload, published on 9 Oct 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official 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.

Weakness: CWE-94 (Improper Control of Generation of Code), CWE-79 (Improper Neutralization of Input During Web Page Generation), CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component), CWE-116 (Improper Encoding or Escaping of Output)

## Which versions are affected by CVE-2025-61773?

3 open source packages ship an affected version, including pyload-ng.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `pyload-ng` | PyPI | All versions | 0.5.0b3.dev91 |
| `pyload-ng` | PyPI | All versions | 0.5.0b3.dev91 |
| `pyload-ng` | PyPI | All versions | 0.5.0b3.dev91 |

## How do I fix CVE-2025-61773?

Upgrade pyload-ng to 0.5.0b3.dev91 or later.

## Is CVE-2025-61773 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-61773 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-61773 and fix it if it is affected.

What it is: CVE-2025-61773 is a high-severity code injection vulnerability in pyload, published on 9 Oct 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-61773 exists.

Affected packages and fixed versions:
- pyload-ng (PyPI): affected all versions; fixed in 0.5.0b3.dev91
- pyload-ng (PyPI): affected all versions; fixed in 0.5.0b3.dev91
- pyload-ng (PyPI): affected all versions; fixed in 0.5.0b3.dev91

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-61773/ (Markdown: https://insights.sbomify.com/CVE-2025-61773/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-61773
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-61773
- OSV: https://osv.dev/vulnerability/CVE-2025-61773

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-61773/
Summaries are generated and may contain mistakes; the official description above is the record.