CVE-2026-109448: postgresql psqlodbc Buffer Underflow

Vulnerability summary

CVE-2026-109448 is a medium (CVSS 5.9) Buffer Underflow vulnerability in postgresql psqlodbc. EPSS estimates a 0.22% chance of exploitation in the next 30 days, higher than 12% of scored vulnerabilities.

Timeline

1. 12-10-2026
   PublishedVulnerability first disclosed.
2. 16-10-2026
   Last modifiedVulnerability information updated.

Description

Integer wraparound in psqlODBC SQLBindParameter allows an application, or an attacker who controls how many parameters the application binds on one statement, to corrupt heap memory. psqlODBC stores the binding count in a signed 16-bit field. Binding parameter number 32768 wraps that count to -32768. Binding parameter 32769 then writes about 2.5 MB of zeros starting 1.25 MB before the binding array, which crashes the application or leaves it running on a corrupted heap. Applications that build parameter lists from untrusted input, such as an IN (?, ?, ...) list, are exposed. Versions before psqlODBC 18.00.0005 are affected.

• CWE-124Buffer Underwrite ('Buffer Underflow')The product writes to a buffer using an index or pointer that references a memory location prior to the beginning of the buffer.
• CWE-190Integer Overflow or WraparoundThe product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.