CVE-2026-79968: Dell Secure Connect Gateway Race Condition

CVE-2026-79968 Overview

CVE-2026-79968 is a Time-of-check Time-of-use (TOCTOU) race condition [CWE-367] in Dell Secure Connect Gateway (SCG) 5.0. The flaw affects Dell SCG 5.0 Appliance versions prior to 5.36.00.16 and Dell SCG 5.0 Application versions prior to 5.36.00.00. An unauthenticated remote attacker can exploit the race window to trigger a denial of service against the gateway. Successful exploitation disrupts the availability of the Secure Connect Gateway, which brokers support connectivity between Dell infrastructure and Dell backend services. No confidentiality or integrity impact is documented for this issue.

Critical Impact
Unauthenticated remote attackers can cause a denial of service on Dell Secure Connect Gateway appliances by winning a TOCTOU race, disrupting Dell support telemetry and remote service connectivity.

Affected Products

Dell Secure Connect Gateway 5.0 Appliance versions prior to 5.36.00.16
Dell Secure Connect Gateway 5.0 Application versions prior to 5.36.00.00
Dell Secure Connect Gateway Virtual Edition (per vendor advisory DSA-2026-382)

Discovery Timeline

2026-09-09 - CVE CVE-2026-79968 published to NVD
2026-09-09 - Last updated in NVD database

Technical Details for CVE-2026-79968

Vulnerability Analysis

The vulnerability is a TOCTOU race condition in Dell Secure Connect Gateway. The affected code path validates a resource or condition at one point in time and then acts on that resource later, without ensuring the state remains consistent between the two operations. An attacker who can reach the gateway over the network can interleave requests so the state observed at check time differs from the state used at operation time. When the race is won, the affected component enters an unexpected state that terminates processing or crashes the service. The attacker requires no credentials and no user interaction, but the attack complexity is high because it depends on precise timing.

Root Cause

The root cause is non-atomic handling of shared state in a network-facing code path within Dell Secure Connect Gateway. The check and the use of the resource are separated by a window during which the resource can be modified, invalidated, or replaced. Because access controls are not enforced across the full check-to-use sequence, concurrent requests can invalidate assumptions made during validation and drive the service into a fault state.

Attack Vector

Exploitation occurs over the network against the Secure Connect Gateway service. The attacker sends concurrent or carefully timed requests that race a legitimate operation between validation and use. Winning the race causes the gateway process or a handler within it to fail, resulting in denial of service. No authentication is required, and no user interaction on the target is needed.

No public proof-of-concept, exploit code, or evidence of in-the-wild exploitation is available for CVE-2026-79968 at the time of publication. Refer to the Dell Security Update Advisory (DSA-2026-382) for vendor-specific technical detail.

Detection Methods for CVE-2026-79968

Indicators of Compromise

Unexpected restarts, crashes, or watchdog-triggered recoveries of the Secure Connect Gateway service or appliance.
Bursts of concurrent or high-rate requests to SCG management or service endpoints from a single source or small set of sources.
Gaps in outbound telemetry from SCG to Dell backend services correlating with request spikes.

Detection Strategies

Monitor SCG process health and service uptime metrics for anomalous restart patterns.
Inspect network flows to the SCG management interface for unusual concurrency, request interleaving, or repeated near-simultaneous calls to the same endpoint.
Correlate SCG availability events with upstream firewall and load balancer logs to identify the source of the request bursts.

Monitoring Recommendations

Enable verbose logging on the SCG appliance and forward logs to a centralized SIEM or data lake for retention and correlation.
Alert on abnormal termination signals, core dumps, or systemd unit failures for SCG components.
Track baseline request rates to SCG endpoints and alert when concurrency or throughput deviates from normal operational patterns.

How to Mitigate CVE-2026-79968

Immediate Actions Required

Upgrade Dell SCG 5.0 Appliance to version 5.36.00.16 or later.
Upgrade Dell SCG 5.0 Application to version 5.36.00.00 or later.
Restrict network access to the SCG management and service interfaces to trusted administrative networks only.
Review SCG service logs and appliance uptime records for signs of prior denial-of-service activity.

Patch Information

Dell has released fixed builds for Dell Secure Connect Gateway. Full remediation details, affected component matrix, and download instructions are published in the Dell Security Update Advisory DSA-2026-382. Apply the patched Appliance build 5.36.00.16 or Application build 5.36.00.00 as appropriate for the deployment.

Workarounds

Place the SCG behind a network access control list that only permits inbound traffic from known management hosts and required Dell service endpoints.
Apply rate limiting and connection throttling upstream of the SCG to reduce the feasibility of high-concurrency race exploitation.
Monitor and automatically restart the SCG service on failure to reduce downtime while patching is scheduled.

bash

# Configuration example: restrict inbound access to the SCG management interface
# Replace 10.0.0.0/24 with your administrative network range
iptables -A INPUT -p tcp --dport 443 -s 10.0.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP