CVE-2026-93395

medium
Assigned by CNA: mongodb
Published 2026-09-17 · Modified 2026-09-17
CVSS v3
5.3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CVSS v4 NEW
6.9
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
VIR risk
5.3

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.

Predictions

Exploit likelihood
63%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

References

CWEs

CWE-191

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.