CVE-2025-66482: Misskey js Misskey Has A Login Rate Vulnerability
MODERATECVE-2025-66482 is a MODERATE (CVSS 6.5) misskey has a login rate vulnerability (CWE-307: Improper Restriction of Excessive Authentication Attempts) affecting Misskey js libraries in the npm ecosystem. The issue involves misskey has a login rate limit bypass via spoofed x-forwarded-for header. Remediation is available by upgrading affected packages to version 2025.12.0-alpha.2.
CVE-2025-66482 at a Glance
Security Impact
CVSS: 6.5
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L).
How to Fix CVE-2025-66482
To remediate this vulnerability, upgrade all affected Misskey js dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
npm install misskey-js@2025.12.0-alpha.2Run the following command in your project directory to verify that all resolved dependencies use the patched release:
npm ls misskey-jsHow to Check if You Are Affected
To determine whether your Node.js application is affected by CVE-2025-66482, inspect your project dependencies using npm:
npm ls misskey-jsAnalyze the terminal output to locate any version of Misskey js in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2025.12.0-alpha.2), your application is affected.
Note: The npm ls misskey-js command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-307: Improper Restriction of Excessive Authentication Attempts, where the product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame. In Misskey js, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2025-66482 Affected Misskey js Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
misskey-js
|
npm |
≥ 2025.9.1
< 2025.12.0-alpha.2
|
2025.12.0-alpha.2
|
References
Frequently Asked Questions
What is CVE-2025-66482?
Which Misskey js versions are affected?
What version fixes CVE-2025-66482?
Is misskey-js affected?
What is the CVSS score of CVE-2025-66482?
What CWE is associated with CVE-2025-66482?
How can I check npm dependencies for CVE-2025-66482?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-wwrj-3hvj-prpm",
"modified" : "2026-01-06T22:41:27Z",
"published" : "2025-12-15T20:59:59Z",
"aliases" : [ "CVE-2025-66482" ],
"summary" : "Misskey has a login rate limit bypass via spoofed X-Forwarded-For header",
"details" : "### Summary\nWhen using an untrusted reverse proxy or not using a reverse proxy at all, attackers 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, making it still vulnerable if the configuration is not set correctly.\n\n### Workaround\n\nIf you are running Misskey with a trusted reverse proxy, you should *not* be affected by this vulnerability.\n\n- There is no workaround for the Misskey itself. Please update Misskey to the latest version or set up a trusted reverse proxy.\n- From v2025.9.1 to v2025.11.1, workaround is available. Set `trustProxy: false` in config file.\n- This is patched in v2025.12.0 by flipping default value of `trustProxy` to `false`. If you are using trusted reverse proxy and not remember you manually overrided this value, please take time to check your config for optimal behavior.\n\n### Details\n[Fastify recommend not trusting X-Forwarded-For IPs](https://fastify.dev/docs/latest/Reference/Server/#trustproxy)\nDue to misconfiguration in https://github.com/misskey-dev/misskey/blob/develop/packages/backend/src/server/api/SigninApiService.ts#L94 attacks can spoof their IPs.\n\n### PoC\n\n```\nPOST /api/signin-flow HTTP/1.1\nHost: misskey.localhost:3123\nContent-Length: 45\nContent-Type: application/json\nConnection: keep-alive\nX-Forwarded-For: 127.1.1.31, 1.1.1.12\n\n{\"username\":\"admin\",\n\t\"password\":\"password\"}\n```\n\n\n\n### Impact\nAn attacker can brute force accounts bypassing rate limiting protection.",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L"
}, {
"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"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "npm",
"name" : "misskey-js"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "2025.9.1"
}, {
"fixed" : "2025.12.0-alpha.2"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"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" : "WEB",
"url" : "https://github.com/misskey-dev/misskey/commit/5512898463fa8487b9e6488912f35102b91f25f7"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/misskey-dev/misskey"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-1188", "CWE-307" ],
"severity" : "MODERATE",
"github_reviewed" : true,
"github_reviewed_at" : "2025-12-15T20:59:59Z",
"nvd_published_at" : "2025-12-16T00:16:02Z"
}
}