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.
Version Information
| Affected branch | Introduced | Fixed In | Fix Published |
|---|---|---|---|
| 14 | — | 14.23 | 2026-05-14 |
| 15 | — | 15.18 | 2026-05-14 |
| 16 | — | 16.14 | 2026-05-14 |
| 17 | — | 17.10 | 2026-05-14 |
| 18 | — | 18.4 | 2026-05-14 |
CVSS 3.0
| Overall Score | 8.8 |
|---|---|
| Component | client |
| Vector | AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
First published: 2026-05-14
Historical source observations
These dated records preserve the original source claims separately from the reviewed fix list.
center · 2026-10-03 12:08:35.169032+08
- PostgreSQL 18 · Original minor coordinate: 4
- PostgreSQL 17 · Original minor coordinate: 10
- PostgreSQL 16 · Original minor coordinate: 14
- PostgreSQL 15 · Original minor coordinate: 18
- PostgreSQL 14 · Original minor coordinate: 23
pgweb · 2026-10-03 12:08:55.967155+08
- PostgreSQL 18 · Original minor coordinate: 4
- PostgreSQL 17 · Original minor coordinate: 10
- PostgreSQL 16 · Original minor coordinate: 14
- PostgreSQL 15 · Original minor coordinate: 18
- PostgreSQL 14 · Original minor coordinate: 23