CVE-2025-66482

MEDIUM

Published Dec 16, 2025 Modified Jan 6, 2026 CWE-307 CWE-1188

Description

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.

CVSS v3.1 Score

6.5

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L

Weakness Type (CWE)

CWE-307 CWE-307

CWE-1188 CWE-1188

Affected Products

Vendor	Product	Versions
misskey	misskey	13.1.0 — 2025.12.0
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All
misskey	misskey	All

References

Advisories & Patches

https://github.com/misskey-dev/misskey/commit/5512898463fa8487b9e6488912f35102b91f25f7 https://github.com/misskey-dev/misskey/security/advisories/GHSA-wwrj-3hvj-prpm https://github.com/misskey-dev/misskey/security/advisories/GHSA-wwrj-3hvj-prpm

Exploits

https://github.com/misskey-dev/misskey/security/advisories/GHSA-wwrj-3hvj-prpm https://github.com/misskey-dev/misskey/security/advisories/GHSA-wwrj-3hvj-prpm

Frequently Asked Questions

What is CVE-2025-66482? +

How severe is CVE-2025-66482? +

CVE-2025-66482 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2025-66482? +

CVE-2025-66482 affects products from misskey, specifically: misskey. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-66482? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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