Sysown Proxysql: Improper Input Validation (CVE-2026-48774)

What is affected, what to do

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.

An exploit is publicly available. Update proxysql to version 4.0.9.

Affected

• Sysown Proxysql gte 3.0.6, < 3.0.9..*

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Metrics

Detection rules

No NEOSEC detection rule is available for this vulnerability yet.

Classification under NIS2 and CRA

Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

NIS2

NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

Read in glossary

High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.

CRA

The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

Read in glossary

From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.

ISO/IEC 27001

ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

Read in glossary

Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

Description

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.

Source: OSV (Open Source Vulnerabilities), NVD (NIST), CVE.org (MITRE), cvelistv5

Vendors and products

• Proxysql ProxySQL
• Sysown Proxysql

Weakness classes (CWE)

• CWE-20Improper Input Validation

  Class

  The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

  Entry at MITRE CWE-20

References & sources

• github.comsysown/proxysql/security/advisories/GHSA-7wh6-2vcc-gcm4x_refsource_CONFIRM, Exploit, Mitigation, Vendor advisory
• github.comsysown/proxysql/commit/e32b7fd50c7c234ea628e392e621e09a2a919e08x_refsource_MISC, Patch
• NVD (NIST)vuln/detail/CVE-2026-48774web

Changes to this CVE

Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

1. 11.08.2026Initial analysis by NVDNVD

   Newly listed as affected:

   • ProxySQL (4.0.6 – before 4.0.9)

   New references:

   • https://github.com/sysown/proxysql/commit/e32b7fd50c7c234ea628e392e621e09a2a919e08
   • https://github.com/sysown/proxysql/security/advisories/GHSA-7wh6-2vcc-gcm4
   Show 4 original changes

   Individual changes of this event as published by NVD

   Type	Action	Before	After
   Product configuration	added	—	OR *cpe:2.3:a:proxysql:proxysql:*:*:*:*:*:*:*:* versions from (including) 4.0.6 up to (excluding) 4.0.9
   Reference type	added	—	GitHub, Inc.: https://github.com/sysown/proxysql/commit/e32b7fd50c7c234ea628e392e621e09a2a919e08 Types: Patch
   Reference type	added	—	GitHub, Inc.: https://github.com/sysown/proxysql/security/advisories/GHSA-7wh6-2vcc-gcm4 Types: Exploit, Mitigation, Vendor Advisory
   Reference type	added	—	CISA-ADP: https://github.com/sysown/proxysql/security/advisories/GHSA-7wh6-2vcc-gcm4 Types: Exploit, Mitigation, Vendor Advisory

   Source identifier: nvd@nist.gov

2. 23.06.2026Record modifiedCISA ADP

   CISA assessment (SSVC): exploitation: proof of concept, automatable: yes

   New references:

   • https://github.com/sysown/proxysql/security/advisories/GHSA-7wh6-2vcc-gcm4
   Show 2 original changes

   Individual changes of this event as published by NVD

   Type	Action	Before	After
   Reference	added	—	https://github.com/sysown/proxysql/security/advisories/GHSA-7wh6-2vcc-gcm4
   SSVC assessment	added	—	{"id":"CVE-2026-48774","role":"CISA Coordinator","options":[{"exploitation":"poc"},{"automatable":"yes"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-06-23T02:22:42.341874Z"}

   Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0

3. 19.06.2026ReceivedGitHub

   CVSS V3.1: AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

   Weakness type: CWE-20

   Description added or changed

   New references:

   • https://github.com/sysown/proxysql/commit/e32b7fd50c7c234ea628e392e621e09a2a919e08
   • https://github.com/sysown/proxysql/security/advisories/GHSA-7wh6-2vcc-gcm4
   Show 6 original changes

   Individual changes of this event as published by NVD

   Type	Action	Before	After
   Affected versions (publisher)	added	—	proxysql
   Description	added	—	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.
   CVSS	added	—	AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
   Weakness type (CWE)	added	—	CWE-20
   Reference	added	—	https://github.com/sysown/proxysql/commit/e32b7fd50c7c234ea628e392e621e09a2a919e08
   Reference	added	—	https://github.com/sysown/proxysql/security/advisories/GHSA-7wh6-2vcc-gcm4

   Source identifier: security-advisories@github.com

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