Junglewise Threat Intelligence

CVE-2026-43436: Linux Kernel NULL pointer dereference in ALSA Scarlett2 mixer interface

CVE-2026-43436 · Severity: medium · CVSS 5.5 · Published 2026-05-08

Technologies: Linux Kernel. Vendors: Linux.

Executive brief

A vulnerability in the Linux kernel's audio driver for Scarlett2 USB devices could allow a local user to crash the system. By connecting a specially crafted or malformed USB device, an attacker can trigger a system failure (NULL pointer dereference). This primarily impacts the availability of the system and any ongoing operations.

Technical details

A NULL pointer dereference vulnerability exists in the Linux kernel's ALSA (Advanced Linux Sound Architecture) subsystem, specifically within the Scarlett2 mixer quirk of the USB-audio driver. The function 'scarlett2_find_fc_interface()' fails to validate the number of endpoints (bNumEndpoints) in a USB interface descriptor before attempting to access them. An attacker with physical access or the ability to emulate USB devices can provide a malformed descriptor with zero endpoints, triggering the dereference. This results in a kernel oops and system crash (Denial of Service). The issue has been resolved by adding a sanity check to skip interfaces with insufficient endpoints.

Affected products

  • Linux Linux Kernel 5.14 to 6.1.167, 6.2 to 6.6.130, 6.7 to 6.12.78, 6.13 to 6.18.19, 6.19 to 6.19.9, 7.0-rc1 to 7.0-rc3

Timeline

  • 2026-03-09: patched: Initial patch authored by Takashi Iwai
  • 2026-05-08: disclosed: CVE published by kernel.org
  • 2026-05-08: advisory

References

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