VIR Vulnerability Intelligence Relay

CVE-2026-84966

medium
Assigned by CNA: mongodb
Published 2026-09-03 · Modified 2026-09-03
Discuss on Community Propose mitigation
CVSS v3
5.1
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4 NEW
5.9
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
VIR risk
5.1

Description

An incorrect numeric type conversion in the BSON document building component of the MongoDB C++ Driver may cause a length value to be interpreted incorrectly. When an application supplies an extremely large, non-terminated field name to the builder, the library may read memory outside the intended buffer and terminate the calling process. No authentication is required, but the calling application must pass the oversized name in a specific form.

Predictions

Exploit likelihood
51%
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-681

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

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