{"id":"CVE-2025-66482","aliases":["GHSA-wwrj-3hvj-prpm"],"url":"https://o3.security/vulnerability/CVE-2025-66482","summary":"Misskey has a login rate limit bypass via spoofed X-Forwarded-For header","details":"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.","published":"2025-12-15T23:18:37.295Z","modified":"2026-08-08T03:48:05.818584529Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"misskey-js","fixedVersion":"2025.12.0-alpha.2"}],"fix":{"url":"https://github.com/misskey-dev/misskey/commit/5512898463fa8487b9e6488912f35102b91f25f7","label":"misskey-dev/misskey@5512898"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/66xxx/CVE-2025-66482.json"},{"type":"ADVISORY","url":"https://github.com/misskey-dev/misskey/security/advisories/GHSA-wwrj-3hvj-prpm"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-66482"},{"type":"FIX","url":"https://github.com/misskey-dev/misskey/commit/5512898463fa8487b9e6488912f35102b91f25f7"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-08T03:48:05.818584529Z"}}