What is CVE-2026-106433?

CVE-2026-106433 is a high-severity vulnerability in MongoDB Libmongocrypt, classified under Access of Resource Using Incompatible Type (Type Confusion). CVSS score: 8.8/10. Published 2026-10-08.

How severe is CVE-2026-106433?

High severity. CVSS v3 base score is 8.8 out of 10.

Vulnerability in MongoDB Libmongocrypt

CVE-2026-106433

Improper state management in MongoDB libmongocrypt can cause provider-specific data to be treated as an incompatible type when cleaning up a key document containing duplicate masterKey fields. An authenticated actor who can modify key vault documents, or a server that returns such a key document, can cause invalid memory access and invalid frees in the client process. This can terminate the application or corrupt process memory.

Published 2026-10-08 · last modified 2026-10-08.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

MongoDB Libmongocrypt

Weakness classification (CWE)

CWE-843 — Access of Resource Using Incompatible Type (Type Confusion)

References

jira.mongodb.org/browse/MONGOCRYPT-964

Frequently asked questions

What is CVE-2026-106433?: CVE-2026-106433 is a high-severity vulnerability in MongoDB Libmongocrypt, classified under Access of Resource Using Incompatible Type (Type Confusion). CVSS score: 8.8/10. Published 2026-10-08.
How severe is CVE-2026-106433?: High severity. CVSS v3 base score is 8.8 out of 10.