CVE-2026-18408 - PostgreSQL psql \unrestrict lets superuser of pg_dump origin server execute arbitrary code in psql client

First Published: 2026/08/13

Important: This assessment evaluates the impact of CVE-2026-18408 on EDB products and services. It links to and details the CVE and supplements that information with EDB's own assessment.

Summary

The psql \unrestrict meta-command bypasses the input-expansion restriction introduced to fix CVE-2025-8714, allowing a malicious superuser of a pg_dump origin server to inject arbitrary code for execution in the psql client during dump restoration. pg_dump, pg_dumpall, and pg_restore (when generating plain-format dumps) are affected. Versions before PostgreSQL 18.5, 17.11, 16.15, 15.19, and 14.24 are affected.

Vulnerability details

CVE-ID: CVE-2026-18408

CVE Publish Date: 2026/08/13

CVSS Base Score: 8.8

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected products and versions

PostgreSQL

  • All versions prior to 18.5
  • All versions prior to 17.11
  • All versions prior to 16.15
  • All versions prior to 15.19
  • All versions prior to 14.24

EnterpriseDB Postgres Advanced Server (EPAS)

  • All versions prior to 18.5
  • All versions prior to 17.11
  • All versions prior to 16.15
  • All versions prior to 15.19
  • All versions prior to 14.24

EnterpriseDB Postgres Extended (PGE)

  • All versions prior to 18.5
  • All versions prior to 17.11
  • All versions prior to 16.15
  • All versions prior to 15.19
  • All versions prior to 14.24

CloudNativePG

  • All operand versions prior to 18.5
  • All operand versions prior to 17.11
  • All operand versions prior to 16.15
  • All operand versions prior to 15.19
  • All operand versions prior to 14.24

Remediation/fixes

PostgreSQL

Affected VersionFixed InFix Published
prior to 18.518.52026-08-13
prior to 17.1117.112026-08-13
prior to 16.1516.152026-08-13
prior to 15.1915.192026-08-13
prior to 14.2414.242026-08-13

EDB Postgres Extended Server

Affected VersionFixed InFix Published
prior to 18.518.52026-08-13
prior to 17.1117.112026-08-13
prior to 16.1516.152026-08-13
prior to 15.1915.192026-08-13
prior to 14.2414.242026-08-13

EDB Postgres Advanced Server

Affected VersionFixed InFix Published
prior to 18.518.52026-08-13
prior to 17.1117.112026-08-13
prior to 16.1516.152026-08-13
prior to 15.1915.192026-08-13
prior to 14.2414.242026-08-13

CloudNativePG

Customer should update to the fixed version of the PostgreSQL operands.

References

Acknowledgement

Source: PostgreSQL.org


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