A heap-based buffer overflow exists in the TLS transport layer of the MongoDB C Driver when built with the Windows platform TLS backend. A remote endpoint that the client connects to can cause the driver to write uncontrolled data outside the bounds of a heap allocation while processing incoming encrypted traffic after the TLS handshake completes. No authentication or user interaction is required, because the affected processing occurs before any application-level authentication completes. Triggering this issue may lead to memory corruption in the client process, disclosure of adjacent heap memory, or termination of the process.

A heap-based buffer overflow exists in the TLS transport layer of the MongoDB C Driver when built with the Windows platform TLS backend. A remote endpoint that the client connects to, or an attacker able to impersonate or redirect the client's connection, can cause the driver to write attacker-supplied data outside the bounds of a heap allocation while processing incoming encrypted traffic. No authentication or user interaction is required, because the affected processing occurs before any application-level authentication completes. Successful exploitation may lead to memory corruption in the client process, disclosure of adjacent heap memory, or termination of the process.

Affected: Ubuntu:Pro:20.04:LTS: mongo-c-driver, Ubuntu:Pro:22.04:LTS: mongo-c-driver, Ubuntu:Pro:24.04:LTS: mongo-c-driver, Ubuntu:26.04:LTS: mongo-c-driver

A heap-based buffer overflow exists in the TLS transport layer of the MongoDB C Driver when built with the Windows platform TLS backend. A remote endpoint that the client connects to can cause the driver to write uncontrolled data outside the bounds of a heap allocation while processing incoming encrypted traffic after the TLS handshake completes. No authentication or user interaction is required, because the affected processing occurs before any application-level authentication completes. Triggering this issue may lead to memory corruption in the client process, disclosure of adjacent heap memory, or termination of the process.