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Fencer Vulns
medium 6.1

CVE-2026-61789 json

DBHub: MySQL and MariaDB comment interpretation bypasses read-only SQL validation

published 2026-10-30 9 d ago modified 2026-11-06 2 d ago also GHSA-j656-3hf2-fvjc , EUVD-2026-114181

cvss
6.1
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 32%
public exploits
0
none known

Summary

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.

Patch / fix

  • npm @bytebase/dbhub 0.22.6

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
2 d ago

Exploit prediction

0.39% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/bytebase/dbhub/security/advisories/GHSA-j656-3hf2-fvjc referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 6.1 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
CNA 4.0 6.1 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected packages

ecosystem package affected fixed in
npm @bytebase/dbhub
<0.22.6
0.22.6

Affected products

  • bytebase dbhub

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.