CVE-2026-61788

@bytebase/dbhub's read-only mode does not prevent database writes

Published Sep 24, 2026 CVSS 3.1 · 7.4 High EPSS < 1% KEV · Not listed
Description
DBHub is a database MCP server for Postgres, MySQL, SQL Server, Oracle, MariaDB, SQLite. Prior to version 0.22.6, setting `readonly = true` on the `execute_sql` tool does not make the connection read-only. The connectors are written to set PostgreSQL `default_transaction_read_only=on` (and open SQLite in `readOnly` mode), but that code is gated on a config value that is never populated, so it never runs. The only thing left enforcing read-only is a classifier that inspects the first keyword of each statement. Any `SELECT` that writes or has side effects through a function call passes it. With an ordinary role this allows sequence tampering; with a privileged role it allows writing arbitrary files on the server (`lo_export`), reading arbitrary host files (`pg_read_file`), and remote code execution (`dblink` + `COPY ... TO PROGRAM`). The HTTP transport is unauthenticated and binds to `0.0.0.0` by default, so this is reachable by any network caller of `/mcp`. Version 0.22.6 patches the issue.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

Source ID Title
Github GHSA Github GHSA GHSA-mwwr-p57h-56pf @bytebase/dbhub's read-only mode does not prevent database writes
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Bytebase
Bytebase dbhub
Vendors & Products Bytebase
Bytebase dbhub
Type Values Removed Values Added
Description DBHub is a database MCP server for Postgres, MySQL, SQL Server, Oracle, MariaDB, SQLite. Prior to version 0.22.6, setting `readonly = true` on the `execute_sql` tool does not make the connection read-only. The connectors are written to set PostgreSQL `default_transaction_read_only=on` (and open SQLite in `readOnly` mode), but that code is gated on a config value that is never populated, so it never runs. The only thing left enforcing read-only is a classifier that inspects the first keyword of each statement. Any `SELECT` that writes or has side effects through a function call passes it. With an ordinary role this allows sequence tampering; with a privileged role it allows writing arbitrary files on the server (`lo_export`), reading arbitrary host files (`pg_read_file`), and remote code execution (`dblink` + `COPY ... TO PROGRAM`). The HTTP transport is unauthenticated and binds to `0.0.0.0` by default, so this is reachable by any network caller of `/mcp`. Version 0.22.6 patches the issue.
Title @bytebase/dbhub's read-only mode does not prevent database writes
Weaknesses CWE-184
CWE-636
CWE-863
References
Metrics cvssV3_1

{'score': 7.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 29, 2026, 3:00 AM
Reserved
Jul 10, 2026, 8:06 PM
Status
Deferred
Published
Sep 24, 2026, 6:17 PM
Modified
Sep 30, 2026, 7:57 PM