Buffer overflow in MongoDB C Driver
CVE-2026-93393
A heap-based buffer overflow exists in the TLS transport layer of the MongoDB C Driver when built with the Windows platform TLS backend. A remote endpoint that the client connects to can cause the driver to write uncontrolled data outside the bounds of a heap allocation while processing incoming encrypted traffic after the TLS handshake completes. No authentication or user interaction is required, because the affected processing occurs before any application-level authentication completes. Triggering this issue may lead to memory corruption in the client process, disclosure of adjacent heap memory, or termination of the process.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.005 (40.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 41st percentile — 40.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
- MongoDB C Driver
- MongoDB Inc. C Driver — versions 2.4.0
Weakness classification (CWE)
References
- jira.mongodb.org/browse/CDRIVER-6417 (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-93393?
- CVE-2026-93393 is a high-severity vulnerability in MongoDB C Driver, classified under Out-of-bounds Write. CVSS score: 8.1/10. Published 2026-09-17.
- How severe is CVE-2026-93393?
- High severity. CVSS v3 base score is 8.1 out of 10.