CVE-2026-6638

Description

SQL injection in PostgreSQL logical replication ALTER SUBSCRIPTION ... REFRESH PUBLICATION allows a subscriber table creator to execute arbitrary SQL with the subscription's publication-side credentials. The attack takes effect at the next REFRESH PUBLICATION. Within major versions 16, 17, and 18, minor versions before PostgreSQL 18.4, 17.10, and 16.14 are affected. Versions before PostgreSQL 16 are unaffected.

How to fix CVE-2026-6638

To remediate CVE-2026-6638, upgrade the affected package to a fixed version below.

• —upgrade to 16.14-r0 or later
• —upgrade to 17.10-r0 or later
• —upgrade to 18.4-r0 or later
• —upgrade to 16.14.0 or later
• —upgrade to 17.10-0+deb13u1 or later
• —upgrade to 18.4-1 or later

Is CVE-2026-6638 being exploited?

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

Affected packages (6)

• from 0, < 16.14-r0
• from 0, < 17.10-r0
• from 0, < 18.4-r0
• >= 16.0.0, < 16.14.0, >= 17.0.0, < 17.10.0, >= 18.0.0, < 18.4.0
• from 0, < 17.10-0+deb13u1
• from 0, < 18.4-1

CVSS scores

References (4)

• ADVISORYsecurity.alpinelinux.org/vuln/CVE-2026-6638
• ADVISORYsecurity-tracker.debian.org/tracker/CVE-2026-6638
• WEBnvd.nist.gov/vuln/detail/CVE-2026-6638
• WEBwww.postgresql.org/support/security/CVE-2026-6638/