---
id: CVE-2026-120057
title: psqlODBC large-object read overflows the application buffer
summary: >-
  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…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H'
cvssSource: cna
cwe:
  - CWE-120
vendor: PostgreSQL
product: psqlODBC
affected:
  - psqlODBC < 18.00.0006
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-11-02T19:17:40.542954Z'
published: '2026-11-02'
updated: '2026-11-02'
sourceUpdated: '2026-11-02T19:43:04.416Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-120057'
references:
  - url: >-
      https://github.com/postgresql-interfaces/psqlodbc/security/advisories/GHSA-qhmr-5339-q33r
tags:
  - cve.org
epss: 0.00244
epssPercentile: 0.15758
ingestedAt: '2026-11-05T19:30:42.808Z'
---

## Overview

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.

## Affected

- `psqlODBC < 18.00.0006`

## Remediation

Upgrade to psqlODBC 18.00.0006 or later. CC_send_function receives the caller's buffer size, clamps the copy to it, and rejects short fixed-size replies.

### Workarounds

Do not fetch large-object (lo) columns from servers that are not authenticated with sslmode=verify-full or an equivalent GSS setting.