{"id":"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.","aliases":["GHSA-wwrj-3hvj-prpm"],"modified":"2026-08-12T03:51:47.391900454Z","published":"2025-12-15T23:18:37.295Z","database_specific":{"cwe_ids":["CWE-1188","CWE-307"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/66xxx/CVE-2025-66482.json","cna_assigner":"GitHub_M"},"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"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/misskey-dev/misskey","events":[{"introduced":"38fde26d603951b389d23ade204f22b0674b2cde"},{"fixed":"3273ca751284d39ff507fe72305fce763111eff9"},{"introduced":"d56fc4186529bf41fe840cb3497f1a363ac84475"},{"fixed":"5512898463fa8487b9e6488912f35102b91f25f7"}],"database_specific":{"extracted_events":[{"introduced":"13.1.0"},{"fixed":"2025.12.0"},{"introduced":"13.0.0-NA"},{"last_affected":"13.0.0-NA"}],"source":["CPE_RANGE","CPE_STRING","REFERENCES"],"cpe":["cpe:2.3:a:misskey:misskey:*:*:*:*:*:*:*:*","cpe:2.3:a:misskey:misskey:13.0.0:-:*:*:*:*:*:*"]}}],"versions":["13.0.0-NA"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-66482.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N"}]}