Vulnerability in MongoDB C Driver

[ Description ]Official description

A weakness in the BSON library's handling of a specialized binary vector data type allows an arithmetic wraparound when computing the number of elements described by an oversized attacker-supplied value. On builds where the platform word size is 32 bits, an application that parses untrusted BSON data can be made to process only a small fraction of the supplied elements while the operation reports success, producing results that disagree with byte-oriented accessors and with 64-bit builds of the same library. No authentication or user interaction is required beyond getting the application to parse the data. The impact is limited to data integrity; memory safety is not affected and no information is disclosed.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• BSI CERT-Bund3 Nov 2026WID-SEC-2026-4328

  MongoDB (EF Core Provider, Atlas SQL, C Treiber, Rust Treiber, Database Tools and Node.js Treiber): Multiple vulnerabilities Translated from German

  Risk mediumCVE-2026-119672CVE-2026-120954CVE-2026-120678+12 more CVEs

[ References ]References

• jira.mongodb.org/browse/CDRIVER-6420