CVE-2026-18411: KARR Security Auth Bypass Vulnerability

CVE-2026-18411 Overview

CVE-2026-18411 affects the KARR Security System and SWDS dealer-installed automotive anti-theft systems. These devices use a shared Bluetooth authentication key across affected units, meaning the same key protects every deployed device. An attacker within Bluetooth range can leverage this weakness to issue unauthorized commands to a target vehicle. Successful exploitation can unlock doors and disable the engine immobilizer. The weakness maps to [CWE-321: Use of Hard-coded Cryptographic Key]. CISA published details in ICS Advisory ICSA-26-216-01.

Critical Impact
An attacker within Bluetooth range can issue unauthorized commands to vehicles protected by KARR or SWDS anti-theft systems, including unlocking doors and defeating engine immobilization.

Affected Products

KARR Security System (dealer-installed automotive anti-theft system)
SWDS dealer-installed automotive anti-theft system
Vehicles equipped with the affected Bluetooth-enabled anti-theft modules

Discovery Timeline

2026-08-05 - CVE-2026-18411 published to NVD
2026-08-05 - Last updated in NVD database
2026 - CISA publishes ICS Advisory ICSA-26-216-01

Technical Details for CVE-2026-18411

Vulnerability Analysis

The KARR and SWDS anti-theft systems rely on Bluetooth communication between an owner's device or key fob and the vehicle-installed module. Both product lines ship with a shared authentication key embedded in every unit. Any party that recovers the key from one device can authenticate to any other device in the affected population. The flaw allows an attacker to bypass the challenge-response layer that would normally restrict command execution to paired owners.

Because the key is static and universal, attackers do not need to intercept or replay a legitimate session. They only need Bluetooth radio proximity to a target vehicle and knowledge of the shared secret. Impact on the vehicle spans door lock control and immobilizer state, which are the primary anti-theft functions the products advertise.

Root Cause

The root cause is a design decision to use a single hard-coded cryptographic key across the product line rather than provisioning per-device keys during manufacturing or installation ([CWE-321]). Per-device secrets would ensure that compromise of one unit does not extend to any other unit. The shared-key model turns a single extraction into a fleet-wide compromise.

Attack Vector

The attack requires adjacent-network access over Bluetooth. An attacker within radio range of a target vehicle sends authenticated Bluetooth commands using the shared key. No user interaction and no prior authorization on the target vehicle are required. The vehicle module accepts the commands as if they originated from a legitimate paired device, triggering door unlock or immobilizer disable actions. Refer to the CISA ICS Advisory ICSA-26-216-01 for further technical context.

Detection Methods for CVE-2026-18411

Indicators of Compromise

Unexpected door unlock events or immobilizer state changes recorded by the vehicle without a corresponding owner action
Unknown Bluetooth devices connecting to the KARR or SWDS module in proximity to the vehicle
Repeated Bluetooth pairing or authentication attempts from unrecognized MAC addresses near the vehicle

Detection Strategies

Review any available diagnostic logs from the anti-theft module for unauthorized command sequences and unfamiliar peer identifiers
Correlate vehicle unlock or immobilizer events with owner presence to identify actions with no legitimate source
Where feasible, capture and analyze nearby Bluetooth advertising and connection traffic for scanners probing the affected modules

Monitoring Recommendations

Monitor fleet or dealership environments for repeat Bluetooth probing of parked vehicles
Track physical security incident reports involving no signs of forced entry as potential exploitation cases
Coordinate with the installing dealer for firmware or configuration updates and event log retrieval

How to Mitigate CVE-2026-18411

Immediate Actions Required

Contact the dealer or installer of the KARR or SWDS system to request remediation guidance and any available firmware updates
Do not rely on the affected system as the sole anti-theft or immobilization control until the shared-key issue is resolved
Consider disabling the Bluetooth control feature of the module if the dealer confirms this option is available

Patch Information

No vendor patch information is included in the referenced advisory. Consult CISA ICS Advisory ICSA-26-216-01 for updates and follow guidance from the KARR and SWDS installers regarding replacement modules or firmware capable of per-device key provisioning.

Workarounds

Park affected vehicles in monitored or access-controlled locations to reduce Bluetooth-range exposure
Layer additional physical anti-theft controls such as steering wheel locks or aftermarket immobilizers that do not share the affected key
Where the module supports it, disable remote Bluetooth command features until per-device keying is available

bash

# No vendor-supplied configuration remediation is available.
# Follow dealer instructions from CISA ICS Advisory ICSA-26-216-01.