CVE-2026-74502

What the bug is

snd_ump_attach_legacy_rawmidi() allocates the legacy conversion array ump->out_cvts and, on the snd_rawmidi_new() error path, frees it with kfree() but leaves ump->out_cvts pointing at the freed memory. When the endpoint is later torn down, snd_ump_endpoint_free() frees ump->out_cvts a second time, resulting in a double free. The host snd-usb-audio driver attaches the legacy rawmidi for any USB MIDI 2.0 (UMP) device, so a device that makes snd_rawmidi_new() fail reaches this path on enumeration. Clear ump->out_cvts after freeing it on the error path so it is not freed again during teardown. Discovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com>

Where it lives

The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.

sound/core/ump.c

What this is

SOUNDMAINTAINERS section matched on sound/ · linux-sound@vger.kernel.org · Maintained

Check it on the machine

grep -wE 'CONFIG_SND|CONFIG_SND_UMP' /boot/config-$(uname -r)

Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.

Show whether Debian builds this, per release

Debian does not build this code in 4 releases. The build rule could not be established for 1 release, so nothing is claimed about those.

• bookworm?
• trixie, forky, sid, bookworm · linux-6.12n

?

not established - no Makefile entry for the affected file

n

not enabled on any flavour - this release does not build the code

Where a release above reads "not established", no build rule for the affected file was found in that release's kernel tree. That is a gap in this lookup, not a finding that the code is absent.

Build switches

CONFIG_SND, CONFIG_SND_UMP

Reads as

all on means the file is compiled; any one off means it is not.

From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages

Signals

Published

2026-08-15 (2 months ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.17%, higher than 5.7% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

unimportantsource

Subsystem

sound/core

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

Introduced	Fixed in	Commit
6.5	6.6.151	e84d2e53a05c
6.5	6.12.103	3302aaeac4f7
6.5	6.18.44	032746c2dd9a
6.5	7.1.8	c57001f55f97
6.5	7.2	70c977815af0

Debian advisories