Bug 2517066 (CVE-2026-74460)

Summary: CVE-2026-74460 kernel: can: ems_usb: validate CPC message lengths
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's `ems_usb` module. This vulnerability occurs because the `ems_usb_read_bulk_callback()` function, which processes Controller Area Network (CAN) Protocol Converter (CPC) messages from a USB receive buffer, does not properly validate the lengths of these messages. An attacker could exploit this by sending specially crafted CPC messages, potentially leading to a denial of service due to a format error when processing the malformed data.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-08-15 12:47:49 UTC 
In the Linux kernel, the following vulnerability has been resolved:

can: ems_usb: validate CPC message lengths

ems_usb_read_bulk_callback() walks CPC messages packed in one USB
receive buffer.

Check that each declared message fits in the URB payload. Also require the
type-specific payload to cover the fields used by the CAN, state, error and
overrun handlers.
Comment 1 Mauro Matteo Cascella 2026-08-19 16:07:57 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081532-CVE-2026-74460-0f76@gregkh/T