RHSA-2026:27718 - Security Advisory

Topic

An update for postgresql16 is now available for Red Hat Enterprise Linux 10.0 Extended Update Support.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

PostgreSQL is an advanced Object-Relational database management system (DBMS). The base postgresql package contains the client programs that you'll need to access a PostgreSQL DBMS server, as well as HTML documentation for the whole system. These client programs can be located on the same machine as the PostgreSQL server, or on a remote machine that accesses a PostgreSQL server over a network connection. The PostgreSQL server can be found in the postgresql-server sub-package.

Security Fix(es):

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

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux for x86_64 - Extended Update Support 10.0 x86_64
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 10.0 s390x
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 10.0 ppc64le
• Red Hat Enterprise Linux for ARM 64 - Extended Update Support 10.0 aarch64
• Red Hat CodeReady Linux Builder for x86_64 - Extended Update Support 10.0 x86_64
• Red Hat CodeReady Linux Builder for Power, little endian - Extended Update Support 10.0 ppc64le
• Red Hat CodeReady Linux Builder for IBM z Systems - Extended Update Support 10.0 s390x
• Red Hat CodeReady Linux Builder for ARM 64 - Extended Update Support 10.0 aarch64
• Red Hat Enterprise Linux for ARM 64 - 4 years of updates 10.0 aarch64
• Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 10.0 s390x
• Red Hat Enterprise Linux for Power, little endian - 4 years of support 10.0 ppc64le
• Red Hat Enterprise Linux for x86_64 - 4 years of updates 10.0 x86_64

Fixes

• BZ - 2477439 - CVE-2026-6475 postgresql: PostgreSQL: Operating system account hijack via symlink following in pg_basebackup and pg_rewind
• BZ - 2477442 - CVE-2026-6477 postgresql: PostgreSQL libpq: Buffer overflow allows server superuser to overwrite client stack memory
• BZ - 2477447 - CVE-2026-6478 postgresql: PostgreSQL: Credential recovery via covert timing channel in MD5 password comparison
• BZ - 2477448 - CVE-2026-6473 postgresql: integer overflow can cause an undersized allocation and an out-of-bounds write

CVEs

• CVE-2026-6472
• CVE-2026-6473
• CVE-2026-6474
• CVE-2026-6475
• CVE-2026-6477
• CVE-2026-6478
• CVE-2026-6479
• CVE-2026-6637
• CVE-2026-6638

References

• https://access.redhat.com/security/updates/classification/#important