CVE-2026-6475

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.

• postgresql postgresql (< 14.23) • postgresql postgresql (>= 15.0 < 15.18) • postgresql postgresql (>= 16.0 < 16.14) • postgresql postgresql (>= 17.0 < 17.10) • postgresql postgresql (>= 18.0 < 18.4)