# CVE-2026-33011: Nest Fastify HEAD Request Middleware Bypass

> Attackers can bypass GET middleware in NestJS Fastify applications by sending HEAD requests, potentially skipping security checks while executing handlers.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 20 Mar 2026
- **Updated:** 20 Mar 2026
- **Also known as:** GHSA-wf42-42fg-fg84

## What is CVE-2026-33011?

CVE-2026-33011 is a high-severity vulnerability in nestjs nest, published on 20 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Nest is a framework for building scalable Node.js server-side applications. In versions 11.1.15 and below, a NestJS application using @nestjs/platform-fastify GET middleware can be bypassed because Fastify automatically redirects HEAD requests to the corresponding GET handlers (if they exist). As a result: middleware will be completely skipped, the HTTP response won't include a body (since the response is truncated when redirecting a HEAD request to a GET handler), and the actual handler will still be executed. This issue is fixed in version 11.1.16.

Weakness: CWE-670 (Always-Incorrect Control Flow Implementation)

## Which versions are affected by CVE-2026-33011?

2 open source packages ship an affected version, including @nestjs/platform-fastify. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `@nestjs/platform-fastify` | npm | All versions | 11.1.16 |
| `@nestjs/platform-fastify` | npm | All versions | 11.1.16 |

Products: Nestjs Nest.

## How do I fix CVE-2026-33011?

Upgrade @nestjs/platform-fastify to 11.1.16 or later.

## Is CVE-2026-33011 being exploited?

There is no known exploitation of CVE-2026-33011 in the wild and no public exploit code.

## Other vulnerabilities in nestjs nest

- [CVE-2026-2293](https://insights.sbomify.com/CVE-2026-2293/): NestJS 11.1.13 - Lack of data validation allowing authentication/authorization bypass (high 8.2)
- [CVE-2026-40879](https://insights.sbomify.com/CVE-2026-40879/): Nest: DoS via Recursive handleData in JsonSocket (TCP Transport) (high 7.5)
- [CVE-2025-69211](https://insights.sbomify.com/CVE-2025-69211/): Nest has a Fastify URL Encoding Middleware Bypass (TOCTOU) (medium 6.9)
- [CVE-2026-35515](https://insights.sbomify.com/CVE-2026-35515/): @nestjs/core Improperly Neutralizes Special Elements in Output Used by a Downstream Component ('Injection') (medium 6.3)
- [CVE-2024-29409](https://insights.sbomify.com/CVE-2024-29409/): nest allows a remote attacker to execute arbitrary code via the Content-Type header (medium 5.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-33011 and fix it if it is affected.

What it is: CVE-2026-33011 is a high-severity vulnerability in nestjs nest, published on 20 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-33011 in the wild and no public exploit code.

Affected packages and fixed versions:
- @nestjs/platform-fastify (npm): affected all versions; fixed in 11.1.16
- @nestjs/platform-fastify (npm): affected all versions; fixed in 11.1.16

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-2026-33011/ (Markdown: https://insights.sbomify.com/CVE-2026-33011/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33011
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33011
- OSV: https://osv.dev/vulnerability/CVE-2026-33011

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33011/
Summaries are generated and may contain mistakes; the official description above is the record.