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.
This vulnerability carries a MEDIUM severity rating with a CVSS v3.1 score of 6.5, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts limited integrity, and limited availability for affected systems. Impacting 1 product from misskey organizations running these solutions should prioritize assessment and patching.
Reported in 2025, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.
2025-12-16T00:16:02.503
2026-06-17T09:56:54.680
Analyzed
CVSSv3.1: 6.5 (MEDIUM)
| Type | Vendor | Product | Version/Range | Vulnerable? |
|---|---|---|---|---|
| Application | misskey | misskey | < 2025.12.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
| Application | misskey | misskey | 13.0.0 | Yes |
SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For misskey's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.