Misskey has a login rate limit bypass via spoofed X-Forwarded-For header
Summary
| CVE | CVE-2025-66482 |
|---|---|
| State | PUBLISHED |
| Assigner | GitHub_M |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2025-12-16 00:16:02 UTC |
| Updated | 2026-10-14 13:10:00 UTC |
| 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. |
Risk And Classification
Primary CVSS: v4.0 6.9 MEDIUM from [email protected]
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Problem Types: CWE-307 | CWE-1188 | CWE-307 CWE-307: Improper Restriction of Excessive Authentication Attempts | CWE-1188 CWE-1188: Insecure Default Initialization of Resource
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 6.9 | MEDIUM | 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/E:X/C... |
| 4.0 | CNA | DECLARED | 6.9 | MEDIUM | 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 |
| 3.1 | [email protected] | Primary | 6.5 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
NonePrivileges Required
NoneUser Interaction
NoneConfidentiality
NoneIntegrity
LowAvailability
LowSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
LowAvailability
LowCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Application | Misskey | Misskey | All | All | All | All |
| Application | Misskey | Misskey | 13.0.0 | - | All | All |
| Application | Misskey | Misskey | 13.0.0 | beta16 | All | All |
| Application | Misskey | Misskey | 13.0.0 | beta21 | All | All |
| Application | Misskey | Misskey | 13.0.0 | beta22 | All | All |
| Application | Misskey | Misskey | 13.0.0 | beta23 | All | All |
| Application | Misskey | Misskey | 13.0.0 | beta24 | All | All |
| Application | Misskey | Misskey | 13.0.0 | beta25 | All | All |
| Application | Misskey | Misskey | 13.0.0 | beta26 | All | All |
| Application | Misskey | Misskey | 13.0.0 | beta27 | All | All |
| Application | Misskey | Misskey | 13.0.0 | beta28 | All | All |
| Application | Misskey | Misskey | 13.0.0 | beta29 | All | All |
| Application | Misskey | Misskey | 13.0.0 | beta30 | All | All |
| Application | Misskey | Misskey | 13.0.0 | beta31 | All | All |
| Application | Misskey | Misskey | 13.0.0 | beta32 | All | All |
| Application | Misskey | Misskey | 13.0.0 | beta33 | All | All |
| Application | Misskey | Misskey | 13.0.0 | beta34 | All | All |
| Application | Misskey | Misskey | 13.0.0 | beta35 | All | All |
| Application | Misskey | Misskey | 13.0.0 | beta36 | All | All |
| Application | Misskey | Misskey | 13.0.0 | beta37 | All | All |
| Application | Misskey | Misskey | 13.0.0 | beta38 | All | All |
| Application | Misskey | Misskey | 13.0.0 | beta39 | All | All |
| Application | Misskey | Misskey | 13.0.0 | beta40 | All | All |
| Application | Misskey | Misskey | 13.0.0 | beta41 | All | All |
| Application | Misskey | Misskey | 13.0.0 | beta42 | All | All |
| Application | Misskey | Misskey | 13.0.0 | beta43 | All | All |
| Application | Misskey | Misskey | 13.0.0 | rc1 | All | All |
| Application | Misskey | Misskey | 13.0.0 | rc10 | All | All |
| Application | Misskey | Misskey | 13.0.0 | rc11 | All | All |
| Application | Misskey | Misskey | 13.0.0 | rc2 | All | All |
| Application | Misskey | Misskey | 13.0.0 | rc3 | All | All |
| Application | Misskey | Misskey | 13.0.0 | rc4 | All | All |
| Application | Misskey | Misskey | 13.0.0 | rc5 | All | All |
| Application | Misskey | Misskey | 13.0.0 | rc6 | All | All |
| Application | Misskey | Misskey | 13.0.0 | rc7 | All | All |
| Application | Misskey | Misskey | 13.0.0 | rc8 | All | All |
| Application | Misskey | Misskey | 13.0.0 | rc9 | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Misskey-dev | Misskey | affected >= 2025.9.1, < 2025.12.0-alpha.2 | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/misskey-dev/misskey/commit/5512898463fa8487b9e6488912f35102b9... | [email protected] | github.com | Patch |
| github.com/misskey-dev/misskey/security/advisories/GHSA-wwrj-3hvj-prpm | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | github.com | Exploit, Vendor Advisory |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.