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CVE PROGRAM SOURCE RECORD6.9 Medium

CVE-2026-93395

Integer Underflow → Heap Out-of-Bounds Read in `bson_new_from_buffer()

Description

A missing lower-bound validation in the bson_new_from_buffer() function of libbson allows an integer underflow when processing BSON data with a zero-length prefix. The function reads a 32-bit document length from the input buffer but does not verify that the value is at least 5 (the minimum valid BSON document size) before using it in an array index calculation. When the length field is zero, the expression used to check the document's null terminator wraps to UINT32_MAX, causing a heap out-of-bounds read that crashes the process. An unauthorized party who can supply crafted BSON input to an application using this API can cause a denial of service.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

MongoDB Inc. C Driver

Default version status: unaffected

  • 2.0.0 to < 2.3.1affected

References