CVE-2026-79730: Dell Secure Connect Gateway Race Condition

CVE-2026-79730 Overview

CVE-2026-79730 is a Time-of-check Time-of-use (TOCTOU) race condition [CWE-367] affecting Dell Secure Connect Gateway (SCG) 5.0. The flaw exists in 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 cause a denial of service on the affected appliance. Dell disclosed the issue in advisory DSA-2026-382 covering multiple vulnerabilities in the Secure Connect Gateway virtual edition. Successful exploitation impacts availability of the gateway service used to broker remote support communications between Dell infrastructure and Dell's back-end systems.

Critical Impact
Unauthenticated network-based attackers can trigger a denial of service against Dell Secure Connect Gateway, disrupting remote support telemetry and monitoring for connected Dell infrastructure.

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 (as covered by DSA-2026-382)

Discovery Timeline

2026-09-09 - CVE-2026-79730 published to the National Vulnerability Database
2026-09-09 - Last updated in NVD database

Technical Details for CVE-2026-79730

Vulnerability Analysis

CVE-2026-79730 is a Time-of-check Time-of-use (TOCTOU) race condition in the Dell Secure Connect Gateway service. The gateway validates a resource, condition, or request property at one point in time and later uses that value under the assumption it is unchanged. An attacker who reaches the network-facing service can interleave requests to modify the state between the check and the use. Winning the race causes the process to operate on an inconsistent state, leading to a fault or resource condition that terminates or hangs the service.

The flaw does not require authentication or user interaction. However, the attack complexity is high because exploitation depends on precise timing to hit the race window. Impact is limited to denial of service. The advisory does not indicate confidentiality or integrity compromise of data at rest, though the CVSS vector reflects low-scope impact across all three properties.

Root Cause

The root cause is improper synchronization between a validation step and a subsequent operation on the same resource, classified as [CWE-367]. Because the checked state is not held under a lock or re-validated atomically, concurrent input from a remote client can alter the resource before the gateway acts on it. Dell has not published exploit-level detail; refer to the Dell Security Advisory DSA-2026-382 for vendor-supplied technical context.

Attack Vector

The attack vector is network-based. An unauthenticated attacker with reachability to the SCG management or communication ports sends concurrent requests engineered to interleave with the vulnerable check-then-use sequence. Repeated attempts increase the probability of hitting the race window and forcing the service into a denial-of-service state.

No public proof-of-concept exploit is available at the time of publication. See the Dell Security Advisory DSA-2026-382 for authoritative details on the affected code paths.

Detection Methods for CVE-2026-79730

Indicators of Compromise

Unexpected restarts, hangs, or crash loops of Dell SCG services on the appliance or application host.
Bursts of concurrent or rapid-fire requests to SCG network-facing ports from a single or small set of source addresses.
Gaps in Dell telemetry or support-assist data flowing from managed Dell infrastructure through the gateway.

Detection Strategies

Monitor SCG service health, process uptime, and systemd or container restart counters for anomalous churn.
Alert on repeated TCP connections or HTTP/HTTPS requests to SCG ports that exceed normal baselines from non-Dell-infrastructure sources.
Correlate SCG availability events with upstream network flow data to identify coordinated pre-crash request patterns.

Monitoring Recommendations

Ingest SCG appliance logs and host-level process telemetry into a centralized SIEM for baseline and anomaly analysis.
Track version and patch level of every SCG deployment against the fixed versions 5.36.00.16 (Appliance) and 5.36.00.00 (Application).
Watch perimeter and internal firewall logs for unauthorized inbound traffic to SCG management interfaces.

How to Mitigate CVE-2026-79730

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.
Inventory all SCG deployments, including virtual editions, and confirm each instance has been patched.
Restrict network reachability of SCG management and communication endpoints to trusted management networks only.

Patch Information

Dell has released fixed versions as documented in Dell Security Advisory DSA-2026-382. Apply Dell SCG 5.0 Appliance 5.36.00.16 or Dell SCG 5.0 Application 5.36.00.00, or later, following Dell's documented upgrade procedure for the virtual edition. Verify successful upgrade by checking the installed build against the advisory before returning the gateway to production.

Workarounds

Place SCG behind a firewall or ACL that permits inbound traffic only from Dell infrastructure and authorized administrators.
Rate-limit or throttle inbound connections to SCG service ports to reduce the feasibility of high-frequency race attempts.
Enable automated restart and health-check policies on the SCG host so that a triggered denial-of-service condition recovers quickly while patching is scheduled.

bash

# Configuration example: restrict SCG management access with iptables
# Replace 10.0.0.0/24 with your authorized management network
iptables -A INPUT -p tcp --dport 443 -s 10.0.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP