dbt-labs dbt-mcp up to 1.19.x OAuth Helper fastapi_app.py dns rebinding

Summaryinfo

A vulnerability classified as critical has been found in dbt-labs dbt-mcp up to 1.19.x. The impacted element is an unknown function of the file src/dbt_mcp/oauth/fastapi_app.py of the component OAuth Helper. The manipulation leads to dns rebinding. This vulnerability is traded as CVE-2026-55837. It is possible to initiate the attack remotely. There is no exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in dbt-labs dbt-mcp up to 1.19.x and classified as critical. This issue affects some unknown processing of the file src/dbt_mcp/oauth/fastapi_app.py of the component OAuth Helper. The manipulation with an unknown input leads to a dns rebinding vulnerability. Using CWE to declare the problem leads to CWE-350. The product performs reverse DNS resolution on an IP address to obtain the hostname and make a security decision, but it does not properly ensure that the IP address is truly associated with the hostname. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-55837 since 06/17/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1583.002 according to MITRE ATT&CK.

Upgrading to version 1.20.0 eliminates this vulnerability.

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Productinfo

Type

• Artificial Intelligence Software

Vendor

• dbt-labs

Name

• dbt-mcp

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5
• 1.6
• 1.7
• 1.8
• 1.9
• 1.10
• 1.11
• 1.12
• 1.13
• 1.14
• 1.15
• 1.16
• 1.17
• 1.18
• 1.19

Website

• Product: https://github.com/dbt-labs/dbt-mcp/

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