# CVE-2026-55837: dbt-mcp: Unauthenticated OAuth Context Endpoint Leaks dbt Platform Tokens

> Unauthenticated endpoint in dbt-mcp leaks OAuth tokens, allowing attackers to access or modify dbt Platform projects and secrets.

- **Severity:** Medium 6.8 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 14 Sep 2026
- **Updated:** 16 Sep 2026
- **Also known as:** GHSA-jr33-mw75-7j8f, PYSEC-2026-2443

## What is CVE-2026-55837?

CVE-2026-55837 is a medium-severity vulnerability in dbt-labs dbt-mcp, published on 14 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

dbt-mcp is a Model Context Protocol server for interacting with dbt. Prior to 1.20.0, the local OAuth helper in src/dbt_mcp/oauth/fastapi_app.py exposes GET /dbt_platform_context without authentication or Host validation after a user completes the dbt Platform OAuth flow. The endpoint returns the full DbtPlatformContext, including access_token and refresh_token values persisted by the context manager, to any process that can reach 127.0.0.1:6785. The absence of TrustedHostMiddleware allows a remote attacker to use DNS rebinding against a victim's browser because the helper accepts arbitrary Host headers, while a co-located process can request the endpoint directly. The stolen tokens provide immediate dbt Platform API access as the victim and persistent access through the refresh token, allowing access to or modification of projects, jobs, environment secrets, and related account data. This issue is fixed in version 1.20.0.

Weakness: CWE-346 (Origin Validation Error), CWE-306 (Missing Authentication for Critical Functionality), CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2026-55837?

3 open source packages ship an affected version, including dbt-mcp.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `dbt-mcp` | PyPI | All versions | 1.20.0 |
| `dbt-mcp` | PyPI | All versions | 1.20.0 |
| `dbt-mcp` | PyPI | All versions | 1.20.0 |

## How do I fix CVE-2026-55837?

Upgrade dbt-mcp to 1.20.0 or later.

## Is CVE-2026-55837 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55837 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-55837 and fix it if it is affected.

What it is: CVE-2026-55837 is a medium-severity vulnerability in dbt-labs dbt-mcp, published on 14 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55837 exists.

Affected packages and fixed versions:
- dbt-mcp (PyPI): affected all versions; fixed in 1.20.0
- dbt-mcp (PyPI): affected all versions; fixed in 1.20.0
- dbt-mcp (PyPI): affected all versions; fixed in 1.20.0

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-2026-55837/ (Markdown: https://insights.sbomify.com/CVE-2026-55837/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-55837
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-55837
- OSV: https://osv.dev/vulnerability/CVE-2026-55837

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-55837/
Summaries are generated and may contain mistakes; the official description above is the record.