PostgreSQL pg_basebackup and pg_rewind can overwrite unrelated files of origin superuser choice
At a glance
Severity
HIGH 8.8
EPSS
EPSS 0.41 % · percentile 35 (2026-10-27)
State
PUBLISHED
Published
Updated
Assigner
PostgreSQL
NVD status
Analyzed
Description
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.
