---
id: "CVE-2026-120057"
kind: "vulnerability"
aliases: ["CVE-2026-120057"]
title: "psqlODBC: large-object reads let a server overwrite client memory"
severity: "high"
cvss: 7.5
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["odbc", "package", "postgresql", "psqlodbc"]
not_affected_if: ["no-large-objects", "trusted-server-over-ssl", "version-18.00.0006-or-later"]
published_at: "2026-11-02T19:18:02+00:00"
first_seen_at: "2026-11-02T19:24:39+00:00"
updated_at: "2026-11-02T19:26:42+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-120057", "first_seen_at": "2026-11-02T19:24:39+00:00"}]
---

# psqlODBC: large-object reads let a server overwrite client memory

psqlODBC, the PostgreSQL ODBC driver, copies a server's reply to a large-object read into the application's buffer without checking its size. A malicious or man-in-the-middle server can overwrite adjacent client memory with bytes it chooses.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed psqlODBC driver version and confirm whether it is below `18.00.0006`.
- Check whether applications fetch large-object (lo) columns through the driver.
- Check the SSL settings: the risk applies when the server is not trusted under the current SSL configuration.

## Fix

- psqlODBC versions before `18.00.0006` are affected; move to `18.00.0006` or later.

## Timeline

- 2026-11-02T19:24:39+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-120057

## Documents

- [advisory] Vendor advisory: github.com https://github.com/postgresql-interfaces/psqlodbc/security/advisories/GHSA-qhmr-5339-q33r

## From the sources

psqlODBC copies the reply to a large-object read (loread) into the application's buffer using the length sent by the server, without comparing it to the buffer size. A server not trusted under current SSL settings, or a man-in-the-middle, can return more bytes than the buffer holds and overwrite adjacent memory in the client process with server-chosen bytes. Fetching any large-object column is sufficient to trigger it. Versions before psqlODBC 18.00.0006 are affected.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_