CVE-2026-6475

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.

How to fix CVE-2026-6475

To remediate CVE-2026-6475, upgrade the affected package to a fixed version below.

—upgrade to 15.18-r0 or later
—upgrade to 16.14-r0 or later
—upgrade to 17.10-r0 or later
—upgrade to 18.4-r0 or later
—upgrade to 14.23.0 or later
—no fix listed
—upgrade to 15.18-0+deb12u1 or later
—upgrade to 17.10-0+deb13u1 or later
—upgrade to 18.4-1 or later

Is CVE-2026-6475 being exploited?

Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.

Affected packages (9)

from 0, < 15.18-r0
from 0, < 16.14-r0
from 0, < 17.10-r0
from 0, < 18.4-r0
from 0, < 14.23.0, >= 15.0.0, < 15.18.0, >= 16.0.0, < 16.14.0, >= 17.0.0, < 17.10.0, >= 18.0.0, < 18.4.0
from 0
from 0, < 15.18-0+deb12u1
from 0, < 17.10-0+deb13u1
from 0, < 18.4-1

CVSS scores

Source	Version	Severity	Vector
osv	CVSS 3.1	HIGH8.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H