CVE-2026-6475 — PostgreSQL pg_basebackup and pg_rewind can overwrite unrelated files of origin superuser choice
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 …
Published: 2026-05-14 · CVSS: 8.8 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7