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DBHub CVE-2026-61742

| EUVDEUVD-2026-86320 CRITICAL
Missing Authentication for Critical Function (CWE-306)
2026-09-24 GitHub_M GHSA-fm8p-53ww-hf6w
9.3
CVSS 4.0 · Vendor: GitHub_M
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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Lure victim to malicious site
  2. Delivery
    DNS-rebind hostname to DBHub host
  3. Exploit
    Browser sends request with matching Origin/Host
  4. Execution
    Origin==Host check bypassed
  5. Persist
    DBHub dispatches MCP tool calls
  6. Impact
    Read/write configured database contents

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A07:2025 - Authentication Failures
ASVS 5.0
V6 - Authentication Authentication required for critical functions
MITRE ATT&CK

1 technique across 1 tactic: Initial Access

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Exploitation Conditions

Requires DBHub started in the non-default HTTP transport mode (--transport http --port 8080), which exposes the unauthenticated HTTP MCP endpoint; the default stdio transport is not affected. Exploitation further requires a victim with network/browser reachability to the DBHub host to load attacker-controlled web content, plus a successful DNS-rebinding window that defeats the Origin==Host check. Impact scope is bounded by DBHub's configured tool permissions and database credentials - read-only tool configs limit this to disclosure, while write-capable configs permit modification. These limiting factors (non-default mode, required browser interaction, rebind timing) substantially reduce realistic exploitability below the raw 9.3 score.

Impact

The CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H, 9.3) presents this as a critical unauthenticated remote flaw, but the real-world risk is meaningfully lower and hinges on non-default deployment. Exploitation requires DBHub to be started in the documented but NON-default HTTP transport mode (--transport http), and the DNS-rebinding attack requires a victim with browser access to the DBHub host to visit an attacker-controlled site - i.e., meaningful user interaction and a timing/rebind window that the pure CVSS vector does not capture. No EPSS score, no CISA KEV listing, and no public POC are present in the input, so there is no public exploit identified at time of analysis and no evidence of active exploitation. There is a conflict between the vendor's PR:N/UI:N/AC:L scoring and the description's own limiting factors (browser interaction, DNS-rebind timing, and impact gated by 'configured tool permissions and database credentials'), which argues the practical severity is lower than 9.3 - closer to a high-complexity, user-interaction-required issue. Treat as a genuine but conditional priority: high impact where HTTP transport is exposed, negligible where the default stdio transport is used.

Exploit ScenarioDerived

An operator runs DBHub with --transport http --port 8080 against a real configured database. A victim on the same network (or the operator themselves) visits an attacker-controlled website, which uses DNS rebinding to make its hostname resolve to the DBHub host; because both Origin and Host then contain the attacker hostname, DBHub's Origin==Host check passes and the page issues MCP tool calls from the victim's browser to read, enumerate, and potentially write database contents. No POC is present in the input and the flaw is not in CISA KEV, so this is no public exploit identified at time of analysis.

Act Now Prioritize within 24-48h. Why: CRITICAL severity + public POC available.
1 public PoC Patch available 0.2% exploitation probability (EPSS)

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AnalysisAIv1 – Sep 24, 2026

Unauthenticated MCP tool invocation in DBHub versions prior to 0.22.5 allows a malicious website to reach the HTTP transport endpoint and dispatch database tool calls against connected Postgres, MySQL, SQL Server, Oracle, MariaDB, or SQLite databases, because the server's Origin-equals-Host check is defeated by DNS rebinding. The flaw applies only when DBHub is launched in the non-default HTTP transport mode (for example --transport http --port 8080); the default stdio transport is unaffected, and exploitation requires a victim's browser to load attacker-controlled content and successfully complete the rebind window, per the independent assessment. No public exploit has been identified at time of analysis, and while the CVSS 4.0 vector scores 9.3, the assessed real-world severity is lower (CVSS 3.1 AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:L), with impact bounded by DBHub's configured tool permissions and database credentials - read-only configurations limit exposure to disclosure.

RemediationAI

Upgrade DBHub to 0.22.5, the vendor-released patch that fixes the unauthenticated HTTP MCP endpoint exposure; details are in the advisory at https://github.com/bytebase/dbhub/security/advisories/GHSA-fm8p-53ww-hf6w. If immediate upgrade is not possible, the most effective mitigation is to stop using HTTP transport and revert to the default stdio transport, which is not exposed to the network and removes the attack surface entirely. When HTTP transport is operationally required, bind the listener to loopback (127.0.0.1) rather than a routable interface so a rebinding browser cannot reach it, or place the endpoint behind an authenticating reverse proxy and restrict access to trusted client hosts - each of these adds a real authentication or network boundary but requires configuration changes to existing deployments and may break remote MCP clients. Additionally, reduce the blast radius by configuring DBHub with a read-only database account and disabling write-capable MCP tools, which limits the primitive to disclosure rather than modification even if the origin check is defeated; note that read-only tooling constrains legitimate AI workflows that need to mutate data.

Affected VersionsENISA

dbhub < 0.22.5

Affected Packages

npm @bytebase/dbhub fix: 0.22.5
euvd dbhub fix: 0.22.5

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 2 packages in npm, euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

DBHub is a Model Context Protocol (MCP) server from Bytebase that exposes database operations as MCP tools to AI clients across Postgres, MySQL, SQL Server, Oracle, MariaDB, and SQLite (CPE cpe:2.3:a:bytebase:dbhub). When run with the documented HTTP transport mode, DBHub starts an HTTP MCP endpoint that performs no authentication of its own; instead it attempts to gate browser-origin access by comparing the request's Origin hostname to the Host hostname and reflecting the validated Origin into Access-Control-Allow-Origin. This control fails against DNS rebinding: once an attacker-controlled hostname is rebound to the victim-accessible DBHub server, both Origin and Host carry the attacker's hostname, so the equality check passes and the request is accepted and dispatched to MCP tool handlers. CWE-306 (Missing Authentication for Critical Function) describes the root cause - a critical function (MCP tool invocation) is reachable without any credential, and the only gate is an origin check that is not a security boundary. Consequence is bounded by DBHub's tool permission configuration and the privileges of the configured database credentials, so a read-only tool set yields disclosure while a write-capable set permits modification.

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Severity by source

Vendor (GitHub_M) PRIMARY 9.3 CRITICAL
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
vuln.today AI 7.1 HIGH

DNS rebinding adds complexity (AC:H) and requires the victim to load attacker content (UI:R); no auth on the exposed endpoint (PR:N); DB read/write yields C:H/I:H, availability limited (A:L).

3.1 AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:L
4.0 AV:N/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N

Primary rating from Vendor (GitHub_M).

CVSS VectorVendor: GitHub_M

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
None
Vulnerable system: Confidentiality
High
Vulnerable system: Integrity
High
Vulnerable system: Availability
High
Subsequent system: Confidentiality
None
Subsequent system: Integrity
None
Subsequent system: Availability
None

Lifecycle Timeline

2
Patch available
Sep 24, 2026 - 19:04 EUVD
CVE Published
Sep 24, 2026 - 17:30 cve.org
CRITICAL 9.3

DescriptionCVE.org

DBHub is a database MCP server for Postgres, MySQL, SQL Server, Oracle, MariaDB, SQLite. Versions prior to 0.22.5 expose an unauthenticated HTTP MCP endpoint when started with the documented HTTP transport mode, for example --transport http --port 8080. The HTTP server attempts to protect browser-origin access by checking whether the Origin hostname equals the Host hostname, then reflecting the validated Origin into Access-Control-Allow-Origin. This does not stop DNS rebinding. After an attacker-controlled hostname rebinds to a victim-accessible DBHub HTTP server, both Origin and Host can contain the attacker-controlled hostname, so DBHub accepts the request and dispatches MCP tool calls. As a result, a malicious website can deterministically invoke DBHub MCP tools from the victim's browser without prompt injection or model involvement. With the default demo configuration this can read and write the demo SQLite database; with a real configured database, the same primitive can read, enumerate, and potentially write database contents depending on DBHub's configured tool permissions and database credentials. Version 0.22.5 fixes the issue.

Technical POC Analysis

CWE-306 Missing Authentication for Critical Function, with CWE-346 Origin Validation Error.

Full technical POC analysis - root cause, step-by-step exploitation and patch breakdown - is part of the Pro and Business plans.

Latest POC

1 public PoC link from github

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Executive ViewAI

Why It Matters

DBHub, a database MCP tool, can expose connected Postgres, MySQL, SQL Server, Oracle, MariaDB, or SQLite databases to unauthorized tool calls when deployed in non-default HTTP transport mode, potentially allowing data disclosure or modification. This affects organizations running DBHub versions prior to 0.22.5 with HTTP transport enabled, particularly where the endpoint is reachable from browser networks. Leadership should care because a successful attack could compromise sensitive database contents and integrity, though exploitation requires user interaction and no public exploit identified at time of analysis.

Business Impact: High
Compensating Controls

No vendor-released patch identified at time of analysis. Interim mitigations: use the default stdio transport instead of HTTP; if HTTP transport is required, restrict access to trusted networks, disable browser-accessible exposure, enforce read-only DB credentials and least-privilege tool permissions, and monitor for anomalous DB tool invocations.

Threat Intelligence Overview

EPSS Score
0.2%
Top 91% exploitable
Prevalence
Low
niche open-source database MCP server, non-default HTTP mode; limited production footprint
Threat Intel
1
1 source
Data Quality
6 sources
Confidence: High
EUVD NVD CVE.org EPSS Vulnrichment GHSA GitHub

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity CRITICAL
CISA KEV No
Public POC Yes
EPSS 0.2%
Patch available Yes
Active threat No
Deciding rule
CRITICAL severity + public POC available
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision
Scheduled
Exploitation
Poc
System Exposure· derived
Open
Automatable
Yes
Human Impact
High
Technical Impact
Total

Priority Score

66
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +46
PoC: +20
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.

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