[security - high] postgresql:16 security update

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

Security Fix(es):

* postgresql: PostgreSQL missing validation of multibyte character length executes arbitrary code (CVE-2026-2006)
* postgresql: PostgreSQL intarray missing validation of type of input to selectivity estimator executes arbitrary code (CVE-2026-2004)
* postgresql: PostgreSQL pgcrypto heap buffer overflow executes arbitrary code (CVE-2026-2005)

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-2026-2003
Improper validation of type "oidvector" in PostgreSQL allows a database user to disclose a few bytes of server memory. We have not ruled out viability of attacks that arrange for presence of confidential information in disclosed bytes, but they seem unlikely. Versions before PostgreSQL 18.2, 17.8, 16.12, 15.16, and 14.21 are affected.
CVE-2026-2004
Missing validation of type of input in PostgreSQL intarray extension selectivity estimator function allows an object creator to execute arbitrary code as the operating system user running the database. Versions before PostgreSQL 18.2, 17.8, 16.12, 15.16, and 14.21 are affected.
CVE-2026-2005
Heap buffer overflow in PostgreSQL pgcrypto allows a ciphertext provider to execute arbitrary code as the operating system user running the database. Versions before PostgreSQL 18.2, 17.8, 16.12, 15.16, and 14.21 are affected.
CVE-2026-2006
Missing validation of multibyte character length in PostgreSQL text manipulation allows a database user to issue crafted queries that achieve a buffer overrun. That suffices to execute arbitrary code as the operating system user running the database. Versions before PostgreSQL 18.2, 17.8, 16.12, 15.16, and 14.21 are affected.

Modularity name: "postgresql"
Stream name: "16"