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.
- 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
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.
Which versions are affected by CVE-2026-55837?
3 open source packages ship an affected version, including dbt-mcp.
| Package | 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.
Sources
Also known as GHSA-jr33-mw75-7j8f, PYSEC-2026-2443.