CVE-2026-106433
Description
A flaw was found in libmongocrypt. This vulnerability allows an authenticated attacker with permissions to modify key vault documents, or a malicious server returning crafted documents, to cause process memory corruption or a Denial of Service (DoS) by crashing the application. The issue occurs during the cleanup of key documents containing duplicate masterKey fields, causing data to be handled as an incompatible type and leading to invalid memory operations. Consequently, the client application may terminate unexpectedly or experience corrupted memory.
Statement
Red Hat Product Security rates this vulnerability as having an Important impact because improper handling of malformed key vault entries can lead to client-side memory corruption and application crashes. Although triggering the issue requires either an untrusted database server or authenticated privileges to modify key vault records, successful exploitation directly compromises process memory integrity. The libmongocrypt package is not part of core Red Hat Enterprise Linux, restricting exposure primarily to environments consuming packages from community repositories such as EPEL or Fedora.
Understanding the Weakness (CWE)
Other
Technical Impact: Varies by Context
When the product accesses the resource using an incompatible type, this could trigger logical errors because the resource does not have expected properties.
Availability,Integrity,Confidentiality
Technical Impact: Read Memory; Modify Memory; Execute Unauthorized Code or Commands; DoS: Crash, Exit, or Restart
If a memory buffer is accessed using an incompatible type, and the allocated buffer is smaller than the type that the code is attempting to access, then an attacker could read or write memory outside the bounds of the buffer, leading to a crash or possibly code execution.
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