---
id: CVE-2025-66482
title: 'Misskey is an open source, federated social media platform'
summary: >-
  Misskey is an open source, federated social media platform. Attackers who use
  an untrusted reverse proxy or not using a reverse proxy at all can bypass IP
  rate limiting by adding a forged X-Forwarded-For header. Starting with version
  202…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L'
cwe:
  - CWE-307
  - CWE-1188
vendor: misskey
product: misskey
affected:
  - 'misskey >= 13.1.0, < 2025.12.0'
  - misskey = 13.0.0
patched:
  - misskey 2025.12.0
published: '2025-12-16'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T13:10:00.187'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-66482'
references:
  - url: >-
      https://github.com/misskey-dev/misskey/commit/5512898463fa8487b9e6488912f35102b91f25f7
    label: security-advisories@github.com
  - url: >-
      https://github.com/misskey-dev/misskey/security/advisories/GHSA-wwrj-3hvj-prpm
    label: security-advisories@github.com
  - url: >-
      https://github.com/misskey-dev/misskey/security/advisories/GHSA-wwrj-3hvj-prpm
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
epss: 0.00339
epssPercentile: 0.25487
ingestedAt: '2026-10-14T13:30:58.434Z'
---

## Overview

Misskey is an open source, federated social media platform. Attackers who use an untrusted reverse proxy or not using a reverse proxy at all can bypass IP rate limiting by adding a forged X-Forwarded-For header. Starting with version 2025.9.1, an option (`trustProxy`) has been added in config file to prevent this from happening. However, it is initialized with an insecure default value before version 2025.12.0-alpha.2, making it still vulnerable if the configuration is not set correctly. This is patched in v2025.12.0-alpha.2 by flipping default value of `trustProxy` to `false`. Users of a trusted reverse proxy who are unsure if they manually overode this value should check their config for optimal behavior. Users are running Misskey with a trusted reverse proxy should not be affected by this vulnerability. From v2025.9.1 to v2025.11.1, workaround is available. Set `trustProxy: false` in config file.

## Affected

- `misskey >= 13.1.0, < 2025.12.0`
- `misskey = 13.0.0`

## Remediation

Upgrade past the affected range:

- `misskey 2025.12.0`