{"cve":"CVE-2025-66482","nvd":{"published":"2025-12-16T00:16:02.503","modified":"2026-10-14T13:10:00.187","status":"Analyzed","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_v4":{"vector":"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","score":6.9},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L","score":6.5},"cwes":["CWE-307","CWE-1188"],"references":["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"],"products":["misskey:misskey"],"source":"nvd","synced_at":"2026-10-19T22:17:07.138532058+00:00"},"epss":{"cve":"CVE-2025-66482","score":0.00339,"percentile":0.27096,"date":"2026-10-26"},"kev":null,"osv":[{"id":"GHSA-wwrj-3hvj-prpm","url":"https://osv.dev/vulnerability/GHSA-wwrj-3hvj-prpm","summary":"Misskey has a login rate limit bypass via spoofed X-Forwarded-For header","modified":"2026-02-03T03:16:38.620107Z","packages":[{"ecosystem":"npm","name":"misskey-js","purl":"pkg:npm/misskey-js","ranges":[">=2025.9.1 <2025.12.0-alpha.2"],"fixed":["2025.12.0-alpha.2"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}