postgresql:12 security update

PostgreSQL is an advanced object-relational database management system (DBMS).

Security Fix(es):

* 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.

CVE-2026-6473
Integer wraparound in multiple PostgreSQL server features allows an unprivileged database user to cause the server to undersize an allocation and write out-of-bounds. This may execute arbitrary code as the operating system user running the database. In applications that pass gigabyte-scale user inputs to the relevant database functions, the application input provider may achieve a segmentation fault. Versions before PostgreSQL 18.4, 17.10, 16.14, 15.18, and 14.23 are affected.
CVE-2026-6478
Covert timing channel in comparison of MD5-hashed password in PostgreSQL authentication allows an attacker to recover user credentials sufficient to authenticate. This does not affect scram-sha-256 passwords, the default in all supported releases. However, current databases may have MD5-hashed passwords originating in upgrades from PostgreSQL 13 or earlier. Versions before PostgreSQL 18.4, 17.10, 16.14, 15.18, and 14.23 are affected.

Modularity name: "postgresql"
Stream name: "12"