Red Hat Security Advisory: postgresql:18 security update

CVE-2026-6473 — postgresql: integer overflow can cause an undersized allocation and an out-of-bounds write CVE-2026-6475 — postgresql: PostgreSQL: Operating system account hijack via symlink following in pg_basebackup and pg_rewind CVE-2026-6477 — postgresql: PostgreSQL libpq: Buffer overflow allows server superuser to overwrite client stack memory CVE-2026-6478 — postgresql: PostgreSQL: Credential recovery via covert timing channel in MD5 password comparison