CVE-2026-48484: pyLoad Denial of Service Vulnerability

MODERATE
Advisory Identifier: GHSA-vq8p-m3wm-gv5f
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CVSS 6.5
CWE-400 CWE-20
Published
Advisory Summary

CVE-2026-48484 is a MODERATE (CVSS 6.5) denial of service vulnerability (CWE-400: Uncontrolled Resource Consumption) affecting pyLoad libraries in the PyPI ecosystem. The issue involves lack of input size validation leads to denial of service (dos) and process termination. Remediation is available by upgrading affected packages to version 0.5.0b3.dev101.

CVE-2026-48484 at a Glance

CVE Identifier CVE-2026-48484
GHSA Identifier GHSA-vq8p-m3wm-gv5f
Severity MODERATE
CVSS v3.1 Base Score 6.5
CWE Classification CWE-400: Uncontrolled Resource Consumption
Affected Product pyLoad
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 6.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2026-48484

To remediate this vulnerability, upgrade all affected pyLoad dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

pyload-ng fixed: 0.5.0b3.dev101 
pip install pyload-ng>=0.5.0b3.dev101
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show pyload-ng

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-48484, inspect your installed packages using pip:

pip show pyload-ng

Analyze the terminal output to locate any version of pyLoad in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.5.0b3.dev101), your application is affected.

Note: The pip show pyload-ng command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-400: Uncontrolled Resource Consumption, where the product does not properly control the allocation and maintenance of a limited resource. In pyLoad, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

## Description: The API `rpc` function in `api_blueprint.py` handles `multipart/form-data` uploads by reading the whole content of the uploaded file into memory with `file.read()`. This occurs before the data is sent to the underlying function. Since there is no size limit set at this point, a large file upload can exhaust the server's available memory which led to process termination. ## VulnerableCode & Path: https://github.com/pyload/pyload/blob/8e447958b8a66c5899775e725a8b90bce6643004/src/pyload/webui/app/blueprints/api_blueprint.py#L73 ## Steps to Reproduce: 1. Log in to pyLoad (or use an API key, here i used api to communicate). 2. Prepare a large file (e.g., 10GB) . ```bash truncate -s 10G large_file.bin ``` 3. Send a multipart request to an API function that accepts a file, such as `check_online_status_container`: ```bash curl -X POST "http://localhost:8000/api/rpc" \ -H "X-API-Key: YOUR_API_KEY" \ -F "func=check_online_status_container" \ -F "container=@large_file.bin" ``` 4. Monitor the server's memory usage. The process will attempt to allocate memory for the entire file and last the process will be killed by the kernel. <img width="1902" height="610" alt="dos-process-kill-poc" src="https://github.com/user-attachments/assets/2b9bfd0f-5b9f-48dd-983f-f97dfcc358cc" /> ## Impact - **Denial of Service (DoS)**: The pyLoad process will be killed by the Operating System's Out-Of-Memory (OOM) killer, or the entire system may become unresponsive due to swap thrashing or memory exhaustion. - **Service Instability**: Any active downloads or tasks will be interrupted. ## Mitigations - **Implement File Size Limits**: Enforce a maximum size for uploaded files in the web server configuration (e.g., Nginx `client_max_body_size`).

CVE-2026-48484 Affected pyLoad Versions

1 component(s)
Fixed Versions:
0.5.0b3.dev101
Product / Package Ecosystem Affected Versions Fixed Version
pyload-ng
pypi/pyload-ng
PyPI
< 0.5.0b3.dev101
0.5.0b3.dev101

References

GitHub Advisory / Wiki ADVISORY
https://github.com/pyload/pyload/security/advisories/GHSA-vq8p-m3wm-gv5f
Security Fix Commit FIX COMMIT
https://github.com/pyload/pyload/commit/461cd66f30fa9e96453fb4d8c5c47467e452363c
pyLoad Source Repository REPOSITORY
https://github.com/pyload/pyload

Frequently Asked Questions

What is CVE-2026-48484?
CVE-2026-48484 is a security vulnerability in pyLoad involving Lack of Input Size Validation Leads to Denial of Service (DoS) and Process Termination under CWE-400: Uncontrolled Resource Consumption.
Which pyLoad versions are affected?
Affected versions include releases prior to 0.5.0b3.dev101 across affected packages: pyload-ng.
What version fixes CVE-2026-48484?
Upgrading to 0.5.0b3.dev101 (or the latest patched release for your respective branch) resolves the vulnerability.
Is pyload-ng affected?
Yes, pyload-ng is affected in releases prior to 0.5.0b3.dev101. Upgrade your dependency to 0.5.0b3.dev101 or later.
What is the CVSS score of CVE-2026-48484?
CVE-2026-48484 has a CVSS v3.1 base score of 6.5 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-48484?
CVE-2026-48484 is classified under CWE-400: Uncontrolled Resource Consumption (The product does not properly control the allocation and maintenance of a limited resource.).
How can I check PyPI dependencies for CVE-2026-48484?
Run the dependency tree command: 'pip show pyload-ng'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-vq8p-m3wm-gv5f",
  "modified" : "2026-10-09T16:26:53Z",
  "published" : "2026-10-09T16:26:53Z",
  "aliases" : [ "CVE-2026-48484" ],
  "summary" : "pyLoad: Lack of Input Size Validation Leads to Denial of Service (DoS) and Process Termination",
  "details" : "## Description:\nThe API `rpc` function in `api_blueprint.py` handles `multipart/form-data` uploads by reading the whole content of the uploaded file into memory with `file.read()`. This occurs before the data is sent to the underlying function. Since there is no size limit set at this point, a large file upload can exhaust the server's available memory which led to process termination.\n\n## VulnerableCode & Path: \nhttps://github.com/pyload/pyload/blob/8e447958b8a66c5899775e725a8b90bce6643004/src/pyload/webui/app/blueprints/api_blueprint.py#L73  \n\n## Steps to Reproduce:\n1. Log in to pyLoad (or use an API key, here i used api to communicate).\n2. Prepare a large file (e.g., 10GB) .\n  ```bash\ntruncate -s 10G large_file.bin\n  ```\n3. Send a multipart request to an API function that accepts a file, such as `check_online_status_container`:\n```bash\ncurl -X POST \"http://localhost:8000/api/rpc\" \\\n     -H \"X-API-Key: YOUR_API_KEY\" \\\n     -F \"func=check_online_status_container\" \\\n     -F \"container=@large_file.bin\"\n```\n4. Monitor the server's memory usage. The process will attempt to allocate memory for the entire file and last the process will be killed by the kernel.\n<img width=\"1902\" height=\"610\" alt=\"dos-process-kill-poc\" src=\"https://github.com/user-attachments/assets/2b9bfd0f-5b9f-48dd-983f-f97dfcc358cc\" />\n\n## Impact\n- **Denial of Service (DoS)**: The pyLoad process will be killed by the Operating System's Out-Of-Memory (OOM) killer, or the entire system may become unresponsive due to swap thrashing or memory exhaustion.\n- **Service Instability**: Any active downloads or tasks will be interrupted.\n\n## Mitigations\n- **Implement File Size Limits**: Enforce a maximum size for uploaded files in the web server configuration (e.g., Nginx `client_max_body_size`).",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "pyload-ng"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.5.0b3.dev101"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/pyload/pyload/security/advisories/GHSA-vq8p-m3wm-gv5f"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pyload/pyload/commit/461cd66f30fa9e96453fb4d8c5c47467e452363c"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/pyload/pyload"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-20", "CWE-400" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-10-09T16:26:53Z",
    "nvd_published_at" : null
  }
}