MEDIUM · 5.3

CVE-2026-93395

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...

Vulnerability 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.

CVSS Score

5.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW

Related Weaknesses (CWE)

References

FAQ

What is CVE-2026-93395?

CVE-2026-93395 is a vulnerability with a CVSS score of 5.3 (MEDIUM). 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...

How severe is CVE-2026-93395?

CVE-2026-93395 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-93395?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.