{"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","slug":"CVE-2025-66482","body":"## Overview\n\nMisskey 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.\n\n## Affected\n\n- `misskey >= 13.1.0, < 2025.12.0`\n- `misskey = 13.0.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `misskey 2025.12.0`","depth":"sunlit","depthScore":36,"depthScoreParts":{"impact":35.8,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}