Auth bypass in Rt-Labs Ab C-Open
CVE-2026-82358
RT-Labs AB C-Open CANopen contains a write protection bypass in the SDO (Service Data Object) server implementation 'src/co_sdo_server.c' that fails to properly validate write permissions when processing download-segment frames. An unauthenticated attacker on the CAN bus can initiate an SDO upload for a read-only Object Dictionary (OD) entry, which sets a data pointer to the read-only object, then send download-segment frames to write to that memory location. The download-segment handler does not verify that a download session is active, allowing any CANopen node to overwrite read-only OD entries using two SDO frames. Note that CANopen protocol operates over CAN bus and does not provide built-in authentication mechanisms. Fixed in 1.1.1.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- 9119a7d8-5eab-497f-8521-727c672e3725 (vendor-advisory)
- 9119a7d8-5eab-497f-8521-727c672e3725 (release-notes)
- 9119a7d8-5eab-497f-8521-727c672e3725 (third-party-advisory)
- 9119a7d8-5eab-497f-8521-727c672e3725 (vdb-entry)
Frequently asked questions
- What is CVE-2026-82358?
- CVE-2026-82358 is a medium-severity vulnerability in Rt-Labs Ab C-Open, classified under Incorrect Authorization. CVSS score: 6.5/10. Published 2026-10-01.
- How severe is CVE-2026-82358?
- Medium severity. CVSS v3 base score is 6.5 out of 10.