# CVE-2026-69183: Security feature bypass in monkeytype

> Attackers bypass rate limits and brute-force protections by spoofing HTTP headers, enabling mail bombing and resource exhaustion in Monkeytype.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 20 Aug 2026
- **Updated:** 20 Aug 2026
- **Also known as:** GHSA-c878-p3jh-mmjf

## What is CVE-2026-69183?

CVE-2026-69183 is a high-severity vulnerability in monkeytypegame monkeytype, published on 20 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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.

Weakness: CWE-644 (Improper Neutralization of HTTP Headers for Scripting Syntax), CWE-307 (Improper Restriction of Excessive Authentication Attempts), CWE-290 (Authentication Bypass by Spoofing)

## Which versions are affected by CVE-2026-69183?


## How do I fix CVE-2026-69183?

No fix has been published for CVE-2026-69183 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-69183 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-69183 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-69183 and fix it if it is affected.

What it is: CVE-2026-69183 is a high-severity vulnerability in monkeytypegame monkeytype, published on 20 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-69183 exists.

Affected product: monkeytypegame monkeytype. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-69183/ (Markdown: https://insights.sbomify.com/CVE-2026-69183/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-69183
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-69183
- OSV: https://osv.dev/vulnerability/CVE-2026-69183

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-69183/
Summaries are generated and may contain mistakes; the official description above is the record.