---
id: CVE-2026-16241
title: >-
  Integer underflow in PostgreSQL ECPG allows a database server administrator to
  achieve temporary denial of service against the ECPG client via sending a
  bytea value lacking the mandatory prefix
summary: >-
  Integer underflow in PostgreSQL ECPG allows a database server administrator to
  achieve temporary denial of service against the ECPG client via sending a
  bytea value lacking the mandatory prefix.  The client overwrites a huge memory
  regio…
severity: low
cvss: 3.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:L'
cwe:
  - CWE-191
vendor: postgresql
product: postgresql
affected:
  - 'postgresql >= 14.0, < 14.24'
  - 'postgresql >= 15.0, < 15.19'
  - 'postgresql >= 16.0, < 16.15'
  - 'postgresql >= 17.0, < 17.11'
  - 'postgresql >= 18.0, < 18.5'
patched:
  - postgresql 18.5
published: '2026-08-13'
updated: '2026-08-29'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-16241'
references:
  - url: 'https://www.postgresql.org/support/security/CVE-2026-16241/'
    label: f86ef6dc-4d3a-42ad-8f28-e6d5547a5007
tags:
  - nvd
epss: 0.00198
epssPercentile: 0.08603
ingestedAt: '2026-08-29T23:43:53.749Z'
---

## Overview

Integer underflow in PostgreSQL ECPG allows a database server administrator to achieve temporary denial of service against the ECPG client via sending a bytea value lacking the mandatory prefix.  The client overwrites a huge memory region with bytes outside attacker knowledge or control.  This typically yields a simple SIGSEGV, but rare cases might achieve client-specific integrity impact via the write.  Versions before PostgreSQL 18.6, 17.11, 16.15, 15.19, and 14.24 are affected.

## Affected

- `postgresql >= 14.0, < 14.24`
- `postgresql >= 15.0, < 15.19`
- `postgresql >= 16.0, < 16.15`
- `postgresql >= 17.0, < 17.11`
- `postgresql >= 18.0, < 18.5`

## Remediation

Upgrade past the affected range:

- `postgresql 18.5`