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 Version | Fixed In | Fix Published |
|---|---|---|
| 18 | 18.4 | 2026-05-14 |
| 17 | 17.10 | 2026-05-14 |
| 16 | 16.14 | 2026-05-14 |
| 15 | 15.18 | 2026-05-14 |
| 14 | 14.23 | 2026-05-14 |
For more information about PostgreSQL versioning, please visit the versioning page.
| Overall Score | 8.8 |
|---|---|
| Component | client |
| Vector | AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
If you wish to report a new security vulnerability in PostgreSQL, please send an email to security@postgresql.org.
For reporting non-security bugs, please see the Report a Bug page.