CVE-2025-66482
Misskey is an open source, federated social media platform.
Published Dec 16, 2025 · updated Oct 14, 2026 · misskey misskey
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 ( ) 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 to . 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 in config file.
Timeline
Detection, updates, and resolution for this record.
Dec 16, 2025 · NIST NVD
Detected
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 ( ) has been added in config file to prevent this from happening. However, it is initialized with an insecure default value before version 2025.12
Oct 14, 2026 · NIST NVD
Updated
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 ( ) has been added in config file to prevent this from happening. However, it is initialized with an insecure default value before version 2025.12
Affected
- cpe misskey/misskeyversion unspecified
- cpe misskey/misskey13.0.0
Sources
- CVE.orgCVE-2025-66482
Official CVE identifier
cve.org - FIRST EPSSCVE-2025-66482
30-day exploitation probability 0.3%
first.org - NIST NVDCVE-2025-66482
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 ( ) has been ad
nvd.nist.gov