PostgreSQL patches 12-year logical decoding RCE flaw

The PostgreSQL project published a security advisory for CVE-2026-6471: logical decoding can dlopen an arbitrary file. A non-superuser who already holds REPLICATION privilege can pick a logical decoding plugin and run code as the operating-system account that runs the server. The project scores it CVSS 3.0 7.2 (AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H) on the core server.

This is an official PostgreSQL security advisory. It is not a CISA Known Exploited Vulnerabilities addition, and it is not an unauthenticated internet-worm notice.

Affected lines are versions before 18.6, 17.11, 16.15, 15.19, and 14.24. The fixes shipped in those releases on 13 August 2026. Some secondary writeups still name 18.5 as the 18-series fix. The project's advisory text uses 18.6.

Cyera calls the bug PostGREShell and says the path has been present since logical decoding landed in 9.4 in 2014. Exploitation also needs wal_level set to logical, a common setting for change-data-capture and standbys.

The patch adds an output_plugin_libraries allowlist. It defaults to pgoutput and test_decoding. The Hacker News says administrators should run SELECT DISTINCT plugin FROM pg_replication_slots before they upgrade, then add any non-default plugin and reload with pg_reload_conf. A restart is not required.

This is not unauthenticated remote code execution. An attacker needs an account that already holds REPLICATION, the privilege used for backups, standbys, and CDC.

The shape is a privileged-path RCE, unlike the unauthenticated JFrog Artifactory auth bypass. It is closer to a trusted-role problem than to the unconfirmed CrowdStrike FalconFlank privilege-escalation claim. The same class of trusted-component code execution shows up in the VMware Workstation and Fusion host-escape patches and the Cisco Nexus 9000 Silicon One root RCE.

Upgrade to 18.6, 17.11, 16.15, 15.19, or 14.24. Inventory plugins with that SELECT, add every third-party plugin (wal2json, decoderbufs, in-house modules) to output_plugin_libraries, reload the config, and tighten which accounts still hold REPLICATION.