CVE-2026-6475

About vulnerability

Symlink following in PostgreSQL pg_basebackup plain format and in pg_rewind allows an origin superuser to overwrite local files, e.g. /var/lib/postgres/.bashrc, that hijack the operating system account. It will remain the case that starting the server after these commands implicitly trusts the origin superuser, due to features like shared_preload_libraries. Hence, the attack has practical implications only if one takes relevant action between these commands and server start, like moving the files to a different VM or snapshotting the VM. Versions before PostgreSQL 18.4, 17.10, 16.14, 15.18, and 14.23 are affected.

Affected product:

AlmaLinux 9.2 ESU , Alpine Linux 3.22 , Alpine Linux 3.23 , Amazon Linux 2 ELS , CentOS 7 ELS , Debian 10 ELS , Debian 12 , Debian 13 , Oracle Linux 7 ELS , RHEL 7 ELS , RHEL 8 ELS , TuxCare 9.6 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS

Affected packages:

postgresql @ 11_11.22 (+36 more)

Symlink following in PostgreSQL pg_basebackup plain format and in pg_rewind allows an origin superuser to overwrite local files, e.g. /var/lib/postgres/.bashrc, that hijack the operating system account. It will remain the case that starting the server after these commands implicitly trusts the origin superuser, due to features like shared_preload_libraries. Hence, the attack has practical implications only if one takes relevant action between these commands and server start, like moving the files to a different VM or snapshotting the VM. Versions before PostgreSQL 18.4, 17.10, 16.14, 15.18, and 14.23 are affected.