CVE-2026-23058 can: ems_usb: ems_usb_read_bulk_callback(): fix URB memory leak

Not scored Published 4 Feb 2026 Updated 11 May 2026

A memory leak in the Linux kernel EMS USB CAN driver allows local attackers to exhaust system memory, causing denial of service.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: Not needed
Fix: Available

What is CVE-2026-23058?

CVE-2026-23058 is a memory corruption vulnerability in Linux, published on 4 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

can: ems_usb: ems_usb_read_bulk_callback(): fix URB memory leak

Fix similar memory leak as in commit 7352e1d5932a ("can: gs_usb: gs_usb_receive_bulk_callback(): fix URB memory leak").

In ems_usb_open(), the URBs for USB-in transfers are allocated, added to the dev->rx_submitted anchor and submitted. In the complete callback ems_usb_read_bulk_callback(), the URBs are processed and resubmitted. In ems_usb_close() the URBs are freed by calling usb_kill_anchored_urbs(&dev->rx_submitted).

However, this does not take into account that the USB framework unanchors the URB before the complete function is called. This means that once an in-URB has been completed, it is no longer anchored and is ultimately not released in ems_usb_close().

Fix the memory leak by anchoring the URB in the ems_usb_read_bulk_callback() to the dev->rx_submitted anchor.

Which versions are affected by CVE-2026-23058?

How do I fix CVE-2026-23058?

Apply the vendor's patch.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-23058 being exploited?

There is no known exploitation of CVE-2026-23058 in the wild and no public exploit code.

Sources

Also known as AZL-77196, BELL-CVE-2026-23058, DEBIAN-CVE-2026-23058, GHSA-7g6w-2p3x-pf3p, ROOT-OS-DEBIAN-11-CVE-2026-23058, ROOT-OS-DEBIAN-12-CVE-2026-23058 and 4 more.