Vulnerability in Misskey (CVE-2025-66482)
Summary
Vulnerability in Misskey (CVE-2025-66482). Risk of unauthorized operations or information disclosure. Exploitable via trustProxy. Mitigation: upgrade to 2025.12.0-alpha.2 or later.
Original description
The description as published by the source.
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.
Source: NIST National Vulnerability Database NVD
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2025-66482 has been found in Misskey.
Attackers can target a specific entry point like trustProxy over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 6.5/10.
What to do: upgrade Misskey to 2025.12.0-alpha.2 or later.
If unsure, ask your IT team or search "Misskey CVE-2025-66482" on the vendor's site.
CVE-2025-66482 (Misskey) — CWE-307 / CVSS v3 6.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: trustProxy / false
Patched: 2025.12.0-alpha.2 — apply immediately
Workaround: set trustProxy: false
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-307) exists in Misskey. Attackers reach the vulnerable code path via trustProxy without authentication.
Check the vendor advisory for the affected versions of Misskey. Attack surface: trustProxy / false.
Severity: Medium (CVSS 6.5/10). Risk of unauthorized operations or information disclosure.
Update to 2025.12.0-alpha.2.
Workaround: set trustProxy: false
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Misskey' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'Misskey' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
Misskeyを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply temporary workaround mitigate
set trustProxy: falseパッチが適用されるまでの応急処置として、set trustProxy: false を実施。回避策の副作用 (機能低下) を確認した上で。
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3Apply patch patch
Upgrade Misskey to 2025.12.0-alpha.2ステージング環境で 2025.12.0-alpha.2 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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4Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- exploit github.com
- patch security-advisories@github.com