CVE Catalog

CVE-2026-93395

MediumCVSS 5.3
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.40%

32th percentile - higher than 32% of all known CVEs

Summary

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.

Risk Assessment

The vulnerability allows a remote attacker to cause a process crash by supplying specially crafted BSON data, leading to denial of service and potentially disrupting applications using libbson.

Recommendation

It is recommended to upgrade libbson to a version containing the fix. Also, avoid processing untrusted BSON data until the upgrade is applied.

Related vulnerabilities

Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS