# CVE-2026-126196: pgEdge Postgres MCP Server read-only mode can be bypassed by SQL statement smuggling through query_database

> Callers can smuggle SQL through query_database on read-only connections to modify data and leave later calls writable; pgEdge users should care.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Harmful if only installed:** No
- **Needs a specific call:** No
- **Fix available:** No
- **Published:** 12 Nov 2026
- **Updated:** 12 Nov 2026
- **Also known as:** GHSA-j7mp-839j-jrm7

## What is CVE-2026-126196?

CVE-2026-126196 is a high-severity security feature bypass vulnerability in pgedge-postgres-mcp, published on 12 Nov 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

pgEdge Postgres MCP Server enables SQL queries against PostgreSQL databases through Model Context Protocol compatible clients. Prior to 1.1.0, query_database on a read_only connection could send unrecognized statements through pgx Exec without bind parameters, selecting PostgreSQL's simple query protocol and allowing multiple semicolon-separated statements in one request. A caller could combine transaction or session state changes with database writes, and pooled session state could leave later calls writable, when the connecting role held write privileges. The flaw affected deployments relying on read_only as a safety boundary, could compromise integrity and availability, and did not add confidentiality impact beyond the reads already permitted by the connection. This issue is fixed in 1.1.0.

Weakness: CWE-89 (Improper Neutralization of Special Elements used in an SQL Command), CWE-693 (Protection Mechanism Failure)

## Which versions are affected by CVE-2026-126196?

Only installations with a non-default setting turned on are exposed.


## How do I fix CVE-2026-126196?

No fix has been published for CVE-2026-126196 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-126196 being exploited?

There is no known exploitation of CVE-2026-126196 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-126196 and fix it if it is affected.

What it is: CVE-2026-126196 is a high-severity security feature bypass vulnerability in pgedge-postgres-mcp, published on 12 Nov 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-126196 in the wild and no public exploit code.
Exposure: Only installations with a non-default setting turned on are exposed.

Affected product: pgedge-postgres-mcp. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-126196/ (Markdown: https://insights.sbomify.com/CVE-2026-126196/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-126196
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-126196
- OSV: https://osv.dev/vulnerability/CVE-2026-126196

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-126196/
Summaries are generated and may contain mistakes; the official description above is the record.