# CVE-2026-48484: pyLoad API denial of service in multipart file upload handling

Source: https://junglewise.ai/threats/cve-2026-48484-pyload-lack-of-input-size-validation-leads-to-denial-of-service  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-09. Updated: 2026-10-09  
License: CC BY 4.0 with a link back

CVE-2026-48484 · Severity: medium · CVSS 6.5 · Published 2026-10-09

pyLoad is a download manager with a web-based API for managing file downloads. An attacker with API access can upload an extremely large file that causes the server to attempt loading the entire file into memory at once, triggering an out-of-memory condition that kills the process and interrupts all active downloads and services.

Technologies: [pyLoad](https://junglewise.ai/threats/technologies/pyload), [pyload-ng (PyPI)](https://junglewise.ai/threats/technologies/pyload-ng). Vendors: [pyLoad](https://junglewise.ai/threats/vendors/pyload), [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2026-48484 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-48484 being exploited in the wild.

**How severe is CVE-2026-48484?** Medium severity, with a CVSS score of 6.5, published 9 October 2026.

**Which products and versions are affected?** pyLoad prior to fix; pyload-ng (PyPI) < 0.5.0b3.dev101, ECOSYSTEM:introduced=0,fixed=0.5.0b3.dev101.

**Is there a fix for CVE-2026-48484?** Yes. pyload-ng (PyPI): upgrade to 0.5.0b3.dev101 or later. Until then: Enforce a maximum file size limit for uploads in the web server configuration, such as the `client_max_body_size` directive in Nginx or equivalent settings in your reverse proxy or application server. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-48484 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-48484?** Check whether you run pyLoad or pyload-ng (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- pyload-ng (PyPI): upgrade to 0.5.0b3.dev101 or later

  ```sh
  pip install "pyload-ng>=0.5.0b3.dev101"
  ```


Enforce a maximum file size limit for uploads in the web server configuration, such as the `client_max_body_size` directive in Nginx or equivalent settings in your reverse proxy or application server.

## Technical details

The rpc function in api_blueprint.py reads entire uploaded file content into memory via file.read() before processing, without enforcing any size limits. An authenticated attacker can exploit this by sending a large multipart/form-data request to any API endpoint accepting file uploads, causing the process to exhaust available memory and be terminated by the OS kernel or system OOM killer.

## Affected products

- pyLoad pyLoad prior to fix

## Identifiers

- CVE-2026-48484
- GHSA-vq8p-m3wm-gv5f
- PYSEC-2026-4293

## Timeline

- 2026-10-09: disclosed
- 2026-10-09: other: Published as GHSA-vq8p-m3wm-gv5f

## Related threats

- [pyLoad API key validation cache authentication bypass](https://junglewise.ai/threats/cve-2026-123816-pyload-is-a-free-and-open-source-download-manager-written-in)
- [pyLoad WindowsPhoneNotify SSRF in notification addon](https://junglewise.ai/threats/cve-2026-123814-pyload-is-a-free-and-open-source-download-manager-written-in)
- [pyLoad unauthenticated template access and information disclosure](https://junglewise.ai/threats/cve-2026-75597-pyload-unauthenticated-access-to-web-path-filename-bypasses)
- [pyload-ng authentication bypass in getUserData/get_userdata](https://junglewise.ai/threats/pyload-ng-getuserdata-get-userdata-exposed-at-perms-any-allow-any-cd197c9d)
- [pyLoad rate-limit bypass and audit-log spoofing via X-Forwarded-For header](https://junglewise.ai/threats/pyload-rate-limit-bypass-and-audit-log-spoofing-via-trusted-client-0df0fd12)