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CVE-2026-42469 Openvehicles CVE debrief

CVE-2026-42469 is a high-severity buffer overflow affecting Open Vehicle Monitoring System 3 (OVMS3) 3.3.005. According to the NVD record, the parser in canformat_canswitch.cpp does not properly validate a CANswitch DLC value, which can allow a remote attacker to send crafted CANswitch frames that may cause a denial of service and, potentially, arbitrary code execution. The vulnerability was published on 2026-05-01 and updated on 2026-05-20.

Vendor
Openvehicles
Product
Open Vehicle Monitoring System Firmware
CVSS
HIGH 8.6
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-01
Original CVE updated
2026-05-20
Advisory published
2026-05-01
Advisory updated
2026-05-20

Who should care

Operators and maintainers of OVMS3 deployments running 3.3.005, especially anyone exposing CAN-facing interfaces or receiving untrusted vehicle/network traffic. Security teams supporting fleet, telemetry, or embedded systems built on OVMS3 should prioritize this CVE because the attack vector is network-based, requires no privileges, and requires no user interaction.

Technical summary

NVD classifies the issue as CVE-2026-42469 with CVSS 3.1 vector AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H and CWE-121 (stack-based buffer overflow). The vulnerable component is canformat_canswitch.cpp in OVMS3 3.3.005. The parser fails to validate a CANswitch DLC value before processing crafted frames, creating a memory safety condition that can disrupt service and may permit code execution. The vulnerable CPE in the NVD record is openvehicles:open_vehicle_monitoring_system_firmware version 3.3.005.

Defensive priority

High. The combination of remote reachability, no authentication requirement, and high availability impact makes this a priority remediation item for affected OVMS3 deployments.

Recommended defensive actions

  • Confirm whether any OVMS3 systems are running version 3.3.005 or an affected firmware build.
  • Review the NVD and linked issue-tracking reference for vendor guidance and remediation status.
  • Restrict exposure of any CAN-facing or remotely reachable interfaces that can receive untrusted frames until a fix is deployed.
  • Apply the vendor-recommended update or workaround as soon as it is available for your deployment.
  • Monitor affected systems for crashes, restarts, or anomalous CANswitch traffic that could indicate attempted exploitation.

Evidence notes

The assessment is based on the NVD CVE record, which lists CVE-2026-42469 as analyzed, identifies OVMS3 3.3.005 as vulnerable, and provides the CVSS vector AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H. The record also cites a third-party advisory and an issue-tracking reference. The CVE description states the parser in canformat_canswitch.cpp does not properly validate a CANswitch DLC value, enabling crafted CANswitch frames to trigger denial of service or possible code execution. No additional remediation details were included in the supplied corpus.

Official resources

Publicly disclosed in the CVE/NVD record on 2026-05-01 and last modified on 2026-05-20.