CVE-2026-72443 — ALSA: usb-audio: Kill MIDI 2.0 URBs before freeing endpoints
In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: Kill MIDI 2.0 URBs before freeing endpoints MIDI 2.0 input URBs are started during snd_usb_midi_v2_create(). A later setup failure can still jump to snd_usb_midi_v2_free(), which currently frees each endpoint and its coherent URB buffers without first stopping the submitted URBs. A completion can then dereference the embedded URB context and endpoint state after they have been freed, or try to resubmit from the stale endpoint. This was observed as a KASAN slab-use-after-free in input_urb_complete(). The buggy scenario involves two paths, with each column showing the order within that path: probe error path: USB completion path: 1. start_input_streams() submits 1. The HCD still owns a input URBs. submitted input URB. 2. A later setup helper returns 2. input_urb_complete() runs an error. with urb->context in ep. 3. snd_usb_midi_v2_free() frees 3. The completion reads ep endpoint storage and URB buffers. state and can requeue URBs. Make the endpoint destructor follow the same teardown ordering used for disconnect when the endpoint has not already been disconnected: publish ep->disconnected, kill the URBs synchronously, and drain the endpoint before freeing URB buffers and endpoint storage. The guard avoids repeating the stop sequence after the normal snd_usb_midi_v2_disconnect_all() path, while still synchronizing the direct MIDI 2.0 create-error free path. Validation reproduced this kernel report: BUG: KASAN: slab-use-after-free in input_urb_complete+0x37/0x1b0 Workqueue: usb_hub_wq hub_event RIP: 0010:_raw_spin_unlock_irq+0x2e/0x50 Read of size 8 Call trace: dump_stack_lvl+0x77/0xb0 print_report+0xce/0x5f0 input_urb_complete+0x37/0x1b0 (sound/usb/midi2.c:186) srso_alias_return_thunk+0x5/0xfbef5 __virt_addr_valid+0x19f/0x330 kasan_report+0xe0/0x110 __usb_hcd_giveback_urb+0x112/0x1d0 dummy_timer+0xaaa/0x19a0 lock_is_held_type+0x9a/0x110 __lock_acquire+0x467/0x28b0 mark_held_locks+0x40/0x70 _raw_spin_unlock_irqrestore+0x44/0x60 lockdep_hardirqs_on_prepare+0xbb/0x1a0 __hrtimer_run_queues+0x101/0x520 hrtimer_run_softirq+0xd0/0x130 handle_softirqs+0x15b/0x670 __irq_exit_rcu+0xd0/0x170 irq_exit_rcu+0xe/0x20 sysvec_apic_timer_interrupt+0x6c/0x80 asm_sysvec_apic_timer_interrupt+0x1a/0x20
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)+2
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 | ≥ d9c99876868c861afd0e9ce2cea407bbc446b3c9 and < bcdd5a7363bdd287253c406a9c0205f5722058e7≥ d9c99876868c861afd0e9ce2cea407bbc446b3c9 and < 3d961032a6e58fa485b3a4c0fe0f649334d887de≥ d9c99876868c861afd0e9ce2cea407bbc446b3c9 and < 4c16176fc11a61b7545464cb47c98b0c8a055fcb≥ d9c99876868c861afd0e9ce2cea407bbc446b3c9 and < 68286258698e15fe75073fb8d017003f8e493db1≥ d9c99876868c861afd0e9ce2cea407bbc446b3c9 and < f199c8a8bdd54296d3458777e70fe82a78bd9817version 6.5 | Vulnerable | CVE Program (cve.org) e CISA ADP |
EPSS over time FIRST
Oct 15, 2026 → Oct 29, 2026 · 14 reading(s) · max 0.21%
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/4c16176fc11a61b7545464cb47c98b0c8a055fcb
- git.kernel.org/stable/c/3d961032a6e58fa485b3a4c0fe0f649334d887de
- git.kernel.org/stable/c/bcdd5a7363bdd287253c406a9c0205f5722058e7
- git.kernel.org/stable/c/f199c8a8bdd54296d3458777e70fe82a78bd9817
- git.kernel.org/stable/c/68286258698e15fe75073fb8d017003f8e493db1
Elsewhere on this site
Related CVEs (same products)
- Unknown CVE-2026-99216 Drivers: hv: Don't reset VMBus connection state on error/exit paths 2d
- Unknown CVE-2026-99215 power: supply: core: prevent unregistering a power supply while a callback runs 2d
- Unknown CVE-2026-99214 drm/vc4: hdmi: Move packet RAM enable to PM runtime 2d
- Unknown CVE-2026-99207 scsi: target: Disable interrupts while holding delayed_cmd_lock 2d
- Unknown CVE-2026-99208 drm/xe/oa: Zero OA buffer at allocation 2d
- Unknown CVE-2026-99209 drm/xe: skip eviction of a BO with no resource 2d
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-2026-72443 is "ALSA: usb-audio: Kill MIDI 2.0 URBs before freeing endpoints", 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 0.21% 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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