PatchTheCVECVE-2026-85035: The can_add_rx_filter_msgq() system call installs a CAN RX filter whose callback (can_msgq_put() in drivers/ca
CVE-2026-85035 is a high-severity flaw (CVSS 8.8) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
The can_add_rx_filter_msgq() system call installs a CAN RX filter whose callback (can_msgq_put() in drivers/can/can_common.c) is handed the caller's struct k_msgq * as user_data. The controller driver stores that raw pointer in its filter table and dereferences it from the RX path every time a matching frame arrives. The system call verifier z_vrfy_can_add_rx_filter_msgq() in drivers/can/can_handlers.c validated the queue only with K_SYSCALL_OBJ(
Why this priority
- High severity
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 8.8 (High) |
| Attack vector | Local |
| Attack complexity | Low |
| Privileges needed | Low |
| User interaction | None |
| EPSS exploit chance | n/a |
| CISA exploited list | No |
| Weakness | CWE-416 |
| Published | 2026-11-03 |
| Last modified | 2026-11-03 |
Last updated 2026-11-03 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Advisories and coverage
Research and news
- Vulners Bulletins: CVE-2026-85035 2026-11-03
- Vulners Bulletins: CVE-2026-85035 Use-after-free via dynamically allocated message queue retained by the CAN RX filter 2026-11-03
- Vulners Bulletins: CVE-2026-85035 Use-after-free via dynamically allocated message queue retained by the CAN RX filter 2026-11-03
- VulDB Recent Entries: CVE-2026-85035 | ZephyrProject Zephyr up to 4.3.1/4.4.x CAN Message Queue drivers/can/can_common.c can_add_rx_filter_msgq user_data use afte 2026-11-03
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-85035?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-85035 being exploited?
CVE-2026-85035 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-85035 affect?
CVE-2026-85035 affects affected software. Severity is high (CVSS 8.8). The can_add_rx_filter_msgq() system call installs a CAN RX filter whose callback (can_msgq_put() in drivers/can/can_common.c) is handed the caller's struct k_msgq * as user_data. The controller driver stores that raw pointer in its filter t
How urgent is CVE-2026-85035?
Priority 31/100. High severity