Heap overflow via oversized decrypted TLS record sequence in Windows Secure Channel stream (CVE-2026-93393) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-93393

Heap overflow via oversized decrypted TLS record sequence in Windows Secure Channel stream

Answer in brief

CVE-2026-93393 records a Unknown severity vulnerability in Heap overflow via oversized decrypted TLS record sequence in Windows Secure Channel stream. The current sources do not mark it as known exploited. The current feed maps MongoDB Inc./C Driver (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 17, 2026Updated Sep 17, 2026Source checked Sep 17, 2026First seen by HOL Sep 17, 2026Material review Sep 17, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps MongoDB Inc./C Driver (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
MongoDB Inc./C Drivergeneric	2.4.0 \|\| 2.3.0 \|\| 2.2.0 \|\| 2.1.0 \|\| 2.0.0 \|\| 1.30.0 \|\| 1.29.0 \|\| 1.28.0 \|\| 1.27.0 \|\| 1.26.0 \|\| 1.25.0 \|\| 1.24.0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for MongoDB Inc./C Driver.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 17, 2026

Sources and claim methodology

Source referencejira.mongodb.org

Upstream source 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, or an attacker able to impersonate or redirect the client's connection, can cause the driver to write attacker-supplied data outside the bounds of a heap allocation while processing incoming encrypted traffic. No authentication or user interaction is required, because the affected processing occurs before any application-level authentication completes. Successful exploitation may lead to memory corruption in the client process, disclosure of adjacent heap memory, or termination of the process.

Quoted source text, attributed separately from HOL analysis.