What is CVE-2026-120678?

CVE-2026-120678 is a high-severity vulnerability in MongoDB C Driver, classified under Missing Release of Memory after Effective Lifetime. CVSS score: 7.5/10. Published 2026-11-03.

How severe is CVE-2026-120678?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in MongoDB C Driver

CVE-2026-120678

A memory management flaw in the MongoDB C Driver's handling of compressed responses may cause the client library to hold on to memory that is never released. An unauthenticated party that controls the database endpoint a client application connects to may cause repeated, unbounded memory growth in that application, which may result in the application becoming unavailable. No credentials, transport security settings, or user interaction are required.

Published 2026-11-03 · last modified 2026-11-03.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 C Driver

Weakness classification (CWE)

CWE-401 — Missing Release of Memory after Effective Lifetime

References

jira.mongodb.org/browse/CDRIVER-6521

Frequently asked questions

What is CVE-2026-120678?: CVE-2026-120678 is a high-severity vulnerability in MongoDB C Driver, classified under Missing Release of Memory after Effective Lifetime. CVSS score: 7.5/10. Published 2026-11-03.
How severe is CVE-2026-120678?: High severity. CVSS v3 base score is 7.5 out of 10.