CVE-2026-74501 — ALSA: usb-audio: fix use-after-free in ump_to_endpoint()
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>
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+1
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux | ≥ ff49d1df79aef7580fe3ac99d17c3f886655d080 and < 49eccef6d6e1c00dac6fb2e7eb6f9206c33e1c37≥ ff49d1df79aef7580fe3ac99d17c3f886655d080 and < 8a7a33b846d6ba695891b8d0040027cdbad8cd52≥ ff49d1df79aef7580fe3ac99d17c3f886655d080 and < cc014ebf803174f0e5d15956dfc5a38413c945ae≥ ff49d1df79aef7580fe3ac99d17c3f886655d080 and < ae388c0e1bf727972096f770f82d12e4f748d1b6≥ ff49d1df79aef7580fe3ac99d17c3f886655d080 and < 4a05b2d1b4642df74f30b6f54843e825c4a2bfd3version 6.5 | Vulnerable | CVE Program (cve.org) e CISA ADP |
EPSS over time FIRST
Oct 15, 2026 → Oct 29, 2026 · 14 reading(s) · max 0.17%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Not enough vector or weakness data: use the affected application’s logs as a starting point.
Timeline
What happened to this CVE, newest first.
- 2026
- Record published
- Affected products added · linux/linux
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
5 on the record
- git.kernel.org/stable/c/8a7a33b846d6ba695891b8d0040027cdbad8cd52
- git.kernel.org/stable/c/ae388c0e1bf727972096f770f82d12e4f748d1b6
- git.kernel.org/stable/c/49eccef6d6e1c00dac6fb2e7eb6f9206c33e1c37
- git.kernel.org/stable/c/cc014ebf803174f0e5d15956dfc5a38413c945ae
- git.kernel.org/stable/c/4a05b2d1b4642df74f30b6f54843e825c4a2bfd3
Elsewhere on this site
Related CVEs (same products)
- Unknown CVE-2026-99216 Drivers: hv: Don't reset VMBus connection state on error/exit paths 1d
- Unknown CVE-2026-99215 power: supply: core: prevent unregistering a power supply while a callback runs 1d
- Unknown CVE-2026-99207 scsi: target: Disable interrupts while holding delayed_cmd_lock 1d
- Unknown CVE-2026-99208 drm/xe/oa: Zero OA buffer at allocation 1d
- Unknown CVE-2026-99209 drm/xe: skip eviction of a BO with no resource 1d
- Unknown CVE-2026-99210 accel/rocket: clear rdev on device init failure 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CVSS score published by NVD, the CNA, CISA or GitHub so far.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No CWE classification.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-74501 is "ALSA: usb-audio: fix use-after-free in ump_to_endpoint()", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.17% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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