---
id: CVE-2026-17347
title: >-
  The MASTER_PASSWORD_HOOK setting, introduced in pgAdmin 4 7.2, lets an
  administrator configure an external command that returns a per-user encryption
  key, with %u in the configured string replaced by the current user's name
summary: >-
  The MASTER_PASSWORD_HOOK setting, introduced in pgAdmin 4 7.2, lets an
  administrator configure an external command that returns a per-user encryption
  key, with %u in the configured string replaced by the current user's name. The
  previous…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-78
  - CWE-88
published: '2026-07-31'
updated: '2026-08-01'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-17347'
references:
  - url: >-
      https://github.com/pgadmin-org/pgadmin4/commit/e7a85767314e7b0fe0b35fe80b9c1af38f48dff6
    label: f86ef6dc-4d3a-42ad-8f28-e6d5547a5007
  - url: >-
      https://github.com/pgadmin-org/pgadmin4/commit/ea7e798aac27174d2bacee1d6e136bed76a95e23
    label: f86ef6dc-4d3a-42ad-8f28-e6d5547a5007
  - url: 'https://github.com/pgadmin-org/pgadmin4/issues/10191'
    label: f86ef6dc-4d3a-42ad-8f28-e6d5547a5007
tags:
  - nvd
epss: 0.00716
epssPercentile: 0.51722
ingestedAt: '2026-08-02T00:16:16.158Z'
---

## Overview

The MASTER_PASSWORD_HOOK setting, introduced in pgAdmin 4 7.2, lets an administrator configure an external command that returns a per-user encryption key, with %u in the configured string replaced by the current user's name. The previous implementation substituted the username directly into the command string and executed the result with subprocess.Popen(..., shell=True). Because the username can originate from an external authentication source (OAuth/OIDC claims, Kerberos, webserver auth) rather than a value pgAdmin fully controls, a username containing shell metacharacters (';', '$()', backticks, pipes, '&&', newlines) allowed an authenticated user to execute arbitrary commands as the pgAdmin service account in any deployment where the configured hook string uses %u.

Fix tokenises the trusted, administrator-configured hook string into an argument vector first (using shlex in POSIX-quoting mode, with backslash-escaping disabled so Windows-style paths are not mis-parsed), substitutes the untrusted username into the individual argv elements, and executes with shell=False. The username is therefore always confined to a single argv element; any shell metacharacters it contains are inert. Administrators whose MASTER_PASSWORD_HOOK previously relied on shell features (pipes, redirection, environment-variable expansion, globbing) within the hook string itself must move that logic into the invoked script, since it is no longer interpreted by a shell.

This issue affects pgAdmin 4: from 7.2 before 9.17.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.