Buffer overflow in MongoDB C Driver

CVE-2026-96746

An out-of-bounds write in the connection-monitoring logic of the MongoDB C Driver may allow an unauthenticated party who controls name resolution and the responses of the hosts named in a client's connection string to write beyond the end of a heap buffer. This may cause the application using the driver to terminate unexpectedly.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H.

EPSS exploit prediction

EPSS: 0.004 (34.1th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 34th percentile — 34.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-96746: held from 0.004 to 0.004.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-96746?
CVE-2026-96746 is a medium-severity vulnerability in MongoDB C Driver, classified under Out-of-bounds Write. CVSS score: 6.5/10. Published 2026-09-24.
How severe is CVE-2026-96746?
Medium severity. CVSS v3 base score is 6.5 out of 10.