CVE-2026-6473

A flaw was found in PostgreSQL. An integer overflow in multiple server features allows an unprivileged database user to cause an undersized memory allocation that leads to an out-of-bounds write. This issue allows an attacker to execute arbitrary code as the operating system user running the database or, in applications that pass gigabyte-scale user inputs to the relevant database functions, to cause a segmentation fault, resulting in a denial of service.

To exploit this flaw, an attacker with minimal access to a database needs to pass extremely large inputs to vulnerable database functions, causing an integer overflow that leads to an out-of-bounds write. This flaw allows an attacker to potentially execute arbitrary code or, more likely, cause a denial of service.

Default Red Hat Enterprise Linux security features, including SELinux enforcement, Address Space Layout Randomization (ASLR) and NX (No-Execute) stack protection, significantly increase the difficulty of achieving arbitrary code execution, limiting the impact of this vulnerability.

Due to these reasons, this vulnerability has been rated with an important severity.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this vulnerability, validate the length of data and the size of objects on all client APIs and web interfaces. Also, block, drop, or truncate oversized string, array, or binary objects before they are passed into backend SQL queries.