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Fencer Vulns
no cvss —

CVE-2026-74501 json

ALSA: usb-audio: fix use-after-free in ump_to_endpoint()

published 2026-08-15 2 mo ago modified 2026-08-17 2 mo ago also EUVD-2026-59694

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 6%
public exploits
0
none known

Summary

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

ALSA: usb-audio: fix use-after-free in ump_to_endpoint()

create_midi2_ump() registers a card-owned snd_ump_endpoint and stores a back-pointer to its per-interface snd_usb_midi2_ump object in ump->private_data, but it never installs an ump->private_free hook and never clears that pointer.

If a later step of snd_usb_midi_v2_create() fails, its error path calls free_all_midi2_umps(), which kfree()s the snd_usb_midi2_ump object while the already-registered endpoint keeps pointing at it. The created /dev/snd/umpC*D* node stays exposed, so the first operation of any UMP open, ump_to_endpoint(), dereferences the dangling ump->private_data and reads rmidi->eps[dir] out of freed memory.

A malicious USB MIDI 2.0 device that makes creation fail after the endpoint is registered can thus trigger a slab use-after-free read on a subsequent open of the UMP node.

Clear the endpoint's back-pointer before freeing the object, and let ump_to_endpoint() tolerate a NULL private_data so the open/close/trigger callbacks fail cleanly (their callers already handle a NULL endpoint) instead of dereferencing a stale pointer.

Discovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com>

Patch / fix

  • Linux Linux 6.6.151, 6.12.103, 6.18.44, 7.1.8, 7.2
  • linux Debian 13 6.12.105-1
  • linux Debian 14 7.1.8-1
  • linux-6.12 Debian 12 6.12.107-1~deb12u1

debian advisories DEBIAN-CVE-2026-74501

  • linux Ubuntu 26.04 LTS 7.0.0-42.42
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1016.17
  • linux-gcp Ubuntu 26.04 LTS 7.0.0-1016.18
  • linux-ibm Ubuntu 26.04 LTS 7.0.0-1017.17
  • linux-riscv Ubuntu 26.04 LTS 7.0.0-42.42.1
  • linux-oracle Ubuntu 26.04 LTS 7.0.0-1015.16
  • linux-hwe-7.0 Ubuntu 24.04 LTS 7.0.0-42.42~24.04.1
  • linux-oem-7.0 Ubuntu 26.04 LTS 7.0.0-1017.17

ubuntu advisories UBUNTU-CVE-2026-74501

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-source Linux Micro 6.0 6.4.0-159998.55.1
  • kernel-default Linux Micro 6.0 6.4.0-159998.55.1
  • kernel-kvmsmall Linux Micro 6.0 6.4.0-159998.55.1
  • kernel-default-base Linux Micro 6.0 6.4.0-159998.55.1.159998.21.42
  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.90.1
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.90.1
  • kernel-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.53.90.1
  • kernel-source SLE Module for Development Tools 15 SP7, SLE Module for Basesystem 15 SP7 6.4.0-150700.53.90.1

suse advisories SUSE-SU-2026:24550-1SUSE-SU-2026:5091-1

  • kernel Azure Linux 3.0 6.6.152.1-1

azure linux advisories AZL-96105

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-74501 updated cvss 4.6

kernel: ALSA: usb-audio: fix use-after-free in ump_to_endpoint()

  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +82 more Red Hat Enterprise Linux 10 kernel
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-selftests-internal
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.17% chance of exploitation in the next 30 days, higher than 6% of all scored CVEs (FIRST EPSS, 2026-11-08).

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

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