Decade-old PostgreSQL flaw turns backup account into a backdoor
Brief
A critical vulnerability in PostgreSQL had remained hidden for more than a decade, potentially turning a routine backup account into a path to full database and server compromise. The issue, dubbed PostGREShell by Cyera Research, exists in the database’s replication functionality and could allow an attacker with a low-privilege account carrying the REPLICATION attribute to load and execute arbitrary code.
“The flaw lets a low-privilege “backup” account load and execute arbitrary code on the database server, achieving remote code execution across Windows, Linux, and macOS,” said Cyera researcher Vladimir Tokarev in a blog post. “That foothold escalates to full PostgreSQL superuser with persistent backdoor access, turning a routine replication account into total database and server compromise.”
The vulnerability, tracked as CVE-2026-6471, affects PostgreSQL versions dating back to 9.