CVE-2026-69183

Monkeytype is a minimalistic and customizable typing test. In 26.26.0 and earlier, the backend rate-limit key generator in backend/src/middlewares/rate-limit.ts uses client-controlled cf-connecting-ip and x-forwarded-for headers before the trust-proxy-derived req.ip value. An unauthenticated attacker can rotate either header to create a new bucket for each request, bypassing rootRateLimiter, badAuthRateLimiter, getKey(), and the getKeyWithUid() fallback used by public endpoints. This permits repeated POST /users/forgotPasswordEmail and verificationEmail requests, mail bombing registered users, consuming Firebase or SMTP quota, evading brute-force protection, and enabling resource exhaustion. Exploitability of cf-connecting-ip depends on deployment topology, but x-forwarded-for and direct-to-origin paths remain affected when those values are not overwritten by a trusted proxy. No fixed version is available as of this review.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/monkeytypegame/monkeytype/security/advisories/GHSA-c878-p3jh-mmjf
https://github.com/monkeytypegame/monkeytype/security/advisories/GHSA-c878-p3jh-mmjf

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-20 17:19

Updated : 2026-08-20 17:19

NVD link : CVE-2026-69183

Mitre link : CVE-2026-69183

CVE.ORG link : CVE-2026-69183

JSON object : View

Products Affected

No product.

CWE

CWE-290

Authentication Bypass by Spoofing

CWE-307

Improper Restriction of Excessive Authentication Attempts

CWE-644

Improper Neutralization of HTTP Headers for Scripting Syntax

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