9.2

CVE-2026-93393: mongodb inc. c driver Out-of-bounds Write

CVSS: 9.2v4.0CriticalAnalyzed
AliasesUBUNTU-CVE-2026-93393DEBIAN-CVE-2026-93393
Published 17-09-2026Last modified 18-09-2026
Open JSON

Vulnerability summary

CVE-2026-93393 is a critical (CVSS 9.2) Out-of-bounds Write vulnerability in mongodb inc. c driver. EPSS estimates a 0.47% chance of exploitation in the next 30 days, higher than 39.1% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.2/10
010
Critical · v4.0 (CVE.org)
EPSS score
0.47%
0%100%
Low · +0.19 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 17-09-2026
    PublishedVulnerability first disclosed.
  2. 18-09-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

7 scores · 4 sources · 2 versions

EPSS trend

Probability

0.47%

Chance of exploitation in the next 30 days

Percentile

39%

Versus all other CVEs

30-day change

+0.19 pp

From 0.28% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.47%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Debian1 product
  • mongo-c-driverAll versions (No fix recorded) | < 2.5.5-1
Mongodb1 product
  • c_driver≥ 1.10.0, < 1.30.11 | ≥ 2.2.0, < 2.5.4
Mongodb inc.1 product
  • c driver2.4.0 | ≥ 2.3.0, ≤ 2.3.3 | ≥ 2.2.0, ≤ 2.2.4 | ≥ 2.1.0, ≤ 2.1.2 | ≥ 2.0.0, ≤ 2.0.2 | ≥ 1.30.0, ≤ 1.30.8 | ≥ 1.29.0, ≤ 1.29.2 | ≥ 1.28.0, ≤ 1.28.1 | ≥ 1.27.0, ≤ 1.27.6 | ≥ 1.26.0, ≤ 1.26.2 | ≥ 1.25.0, ≤ 1.25.4 | ≥ 1.24.0, ≤ 1.24.4
Ubuntu1 product
  • mongo-c-driverAll versions (No fix recorded)

4 vendors · 4 products

References

4 links