Skip to main content

Boteraser | Website and Server Security Solutions

🛡️ CVE-2026-48774 — proxysql

🟠 CVSS 8.0 — High ⚠️ Exploit Public CWE-20 OSV
8.0
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

ProxySQL MCP run_sql_readonly executes side-effecting MySQL multi-statements despite read-only contract

ProxySQL is a proxy for MySQL and its forks, as well as PostgreSQL. In versions 3.0.0 through 3.0.8, ProxySQL's GenAI/MCP run_sql_readonly tool violates its documented read-only contract for MySQL targets. The tool validates only the full input string with a substring blacklist and first-keyword allowlist, but then executes the entire SQL string on a backend connection created with CLIENT_MULTI_STATEMENTS. As a result, a caller can submit a read-only first statement followed by a side-effecting second statement, such as SELECT 1; RENAME TABLE .... The validator accepts the payload because it starts with SELECT and because side-effecting MySQL statements such as RENAME TABLE, SET, RESET, LOCK TABLES, and KILL are not rejected by the blacklist. In a live MCP runtime test, the /mcp/query endpoint accepted a run_sql_readonly request. The MCP response reported success for the first SELECT, and direct backend verification showed that the table had actually been renamed. This violates the endpoint's read-only security contract and lets an MCP caller perform backend writes or administrative SQL, limited by the configured MCP target account's database privileges. Version 3.0.9 contains a fix. Other operator mitigations include: keeping MCP disabled unless required; setting a non-empty mcp-query_endpoint_auth token before exposing /mcp/query; restricting MCP listener network exposure; configuring MCP backend target credentials as database-level read-only users; and adding temporary MCP query rules to block obvious multi-statement patterns.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity high, availability none.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

  • Attack vector: Network — reachable from anywhere that can route to the service.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: None — an unauthenticated stranger can try it.
  • User interaction: None — nobody has to be tricked into anything.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: None.
  • Integrity impact: High — total loss, or loss the attacker controls.
  • Availability impact: None.

Weakness class

CVE-2026-48774 is classified as CWE-20: Improper Input Validation. The application accepts input without checking that it has the expected form, so malformed values reach code that assumes they are well formed.

Affected software

CVE-2026-48774 is recorded against 1 package.

  • proxysql

Timeline and source

Published on 17 August 2026. A public exploit is known to exist, which raises the urgency of patching considerably. A vendor advisory or fix has been published. Record sourced from OSV.

References

github.com (Web)
github.com (Web)
nvd.nist.gov (Web)

Other advisories for this package

proxysql has other advisories on record. If you are patching this one, these are worth checking on the same host:

Same weakness in other software

These advisories are the same class of weakness (CWE-20: Improper Input Validation) in other software:

Details

Severity HIGH
CVSS Score 8.0
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CWE CWE-20
Public Exploit ⚠️ Yes
Source OSV
Published 2026-08-17
Updated 2026-08-20
Modified 2026-08-17

Affected Packages

Software From version Fixed in
proxysql — —

Similar Threats

Exploit Protection

Are you running proxysql?

CVE-2026-48774 carries CVSS 8.0 High rating and a public exploit already exists. BotEraser checks your installation against this and other known CVE records, and blocks IPs associated with exploit activity.

Check My Site For CVE-2026-48774 →

No credit card required  ·  Results in minutes

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

Browse related advisories

All advisoriesCVECVE 2026
✓