CVE-2026-79973: Dell Secure Connect Gateway DOS Vulnerability

CVE-2026-79973 Overview

CVE-2026-79973 affects Dell Secure Connect Gateway (SCG) 5.0, both the appliance and application editions. The vulnerability stems from unsynchronized access to shared data in a multithreaded context [CWE-567]. A low-privileged attacker with remote access can trigger the flaw to cause a denial of service condition on the affected gateway.

Dell addressed the issue in SCG 5.0 Appliance version 5.36.00.16 and SCG 5.0 Application version 5.36.00.00. Administrators running earlier releases should apply the vendor update from Dell Security Update DSA-2026-382.

Critical Impact
Successful exploitation disrupts availability of the Secure Connect Gateway service, breaking Dell remote support telemetry and update workflows for connected infrastructure.

Affected Products

Dell SCG 5.0 Appliance versions prior to 5.36.00.16
Dell SCG 5.0 Application versions prior to 5.36.00.00
Dell Secure Connect Gateway virtual edition

Discovery Timeline

2026-09-09 - CVE-2026-79973 published to the National Vulnerability Database
2026-09-09 - Last updated in NVD database

Technical Details for CVE-2026-79973

Vulnerability Analysis

The flaw is classified as unsynchronized access to shared data in a multithreaded context [CWE-567]. Multiple threads within the SCG service read and write shared state without adequate locking or memory-ordering guarantees. When concurrent requests race, the resulting inconsistent state drives the service into an unrecoverable condition and terminates request processing.

Exploitation requires network reachability and authenticated low-level access to the gateway. No user interaction is needed. The impact is limited to availability disruption of the Secure Connect Gateway itself, with confidentiality and integrity effects constrained to information handled during the race window.

Root Cause

The root cause is missing synchronization primitives around shared data structures accessed by concurrent worker threads. Without proper mutex, atomic, or lock-free coordination, one thread can observe a partially updated object written by another. This inconsistent view triggers logic errors that propagate into a denial of service.

Attack Vector

An attacker with valid low-privilege credentials sends concurrent requests over the network to endpoints that operate on shared state. Repeated concurrent invocations increase the probability of hitting the race window. Dell has not published exploitation details, and no public proof of concept is available. Refer to the Dell DSA-2026-382 advisory for vendor-supplied technical context.

Detection Methods for CVE-2026-79973

Indicators of Compromise

Unexpected restarts, crashes, or hangs of the Dell Secure Connect Gateway service
Sudden loss of telemetry or callhome events from managed Dell infrastructure connected through SCG
Bursts of concurrent authenticated requests from a single low-privilege account to the SCG management interface

Detection Strategies

Monitor SCG process supervisor logs for repeated worker thread termination or service restart loops
Alert on authentication events where a low-privilege SCG account issues high-rate parallel API calls
Correlate SCG availability gaps with network flow spikes to the gateway management ports

Monitoring Recommendations

Ingest SCG application and appliance logs into a centralized SIEM for baseline availability tracking
Track the SCG service uptime metric and page on unplanned restarts
Review Dell SupportAssist connectivity dashboards for gaps that align with anomalous request patterns

How to Mitigate CVE-2026-79973

Immediate Actions Required

Upgrade SCG 5.0 Appliance to version 5.36.00.16 or later
Upgrade SCG 5.0 Application to version 5.36.00.00 or later
Audit local SCG accounts and remove or rotate low-privilege credentials that are no longer required
Restrict network reachability of the SCG management interface to trusted administrative subnets

Patch Information

Dell released fixed builds under Dell Security Update DSA-2026-382. Apply the update through the standard SCG upgrade workflow and validate that the running version matches or exceeds the fixed release before returning the appliance to production.

Workarounds

Place the SCG management interface behind a firewall that limits access to known administrative hosts
Enforce rate limiting on authenticated API endpoints via an upstream reverse proxy where feasible
Disable or lock SCG accounts that are not actively required for support operations until patching completes

bash

# Verify installed Dell SCG version before and after patching
# Replace <scg-host> with the appliance FQDN
ssh admin@<scg-host> 'scg-cli system version'

# Expected fixed versions:
# Appliance: 5.36.00.16 or later
# Application: 5.36.00.00 or later