CVE Intelligence
Unknown

CVE-2025-39997 — ALSA: usb-audio: fix race condition to UAF in snd_usbmidi_free

In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: fix race condition to UAF in snd_usbmidi_free The previous commit 0718a78f6a9f ("ALSA: usb-audio: Kill timer properly at removal") patched a UAF issue caused by the error timer. However, because the error timer kill added in this patch occurs after the endpoint delete, a race condition to UAF still occurs, albeit rarely. Additionally, since kill-cleanup for urb is also missing, freed memory can be accessed in interrupt context related to urb, which can cause UAF. Therefore, to prevent this, error timer and urb must be killed before freeing the heap memory.

Published Oct 15, 2025 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: Linux

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
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.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.21%
ahead of 11% of scored CVEs · Oct 15, 2026
Affects
Linux
Linux
CVSS base
—
Score not published yet.

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.

  1. Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
  2. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  3. Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Linux Linux ≥ 06513dd6d32c37d0364db8488cfdf3e14da238a8 and < e63f049c7764b615d1d50cb486745fa63372b42d≥ efaf61052b8ff9ee8968912fbaf02c2847c78ede and < e16985513e89466a236d2a7c202783b4dd0c5a46≥ 647410a7da46067953a53c0d03f8680eff570959 and < dc4874366cf6cf4a31d8fa4b7f0e2a5b2d7647ba≥ c611b9e55174e439dcd85a72969b43a95f3827a4 and < 647d6b8d22be12842fde6ed0c56859ebc615f21e≥ 0718a78f6a9f04b88d0dc9616cc216b31c5f3cf1 and < af600e7f5526d16146b3ae99f6ad57bfea79ca33≥ 0718a78f6a9f04b88d0dc9616cc216b31c5f3cf1 and < 353d8c715cc951a980728133c9dd64ca5a0a186c≥ 0718a78f6a9f04b88d0dc9616cc216b31c5f3cf1 and < 9f2c0ac1423d5f267e7f1d1940780fc764b0fee3version 62066758d2ae169278e5d6aea5995b1b6f6ddeb5
and 3 more ≥ 6.1.167 and < 6.1.175≥ 6.15.3 and < 6.16version 6.16
Vulnerable CVE Program (cve.org) e CISA ADP

EPSS over time FIRST

Oct 13, 2026 → Oct 15, 2026 · 3 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.
application logs

Timeline

What happened to this CVE, newest first.

  • 2026
  • Record published
    Oct 13, 2026
  • Affected products added · linux/linux
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Source status changed · → Deferred
    Oct 13, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 13, 2026 · NIST National Vulnerability Database
  • 2025
  • CVE published
    Oct 15, 2025 · Linux

Source activity

Repeated readings are counted rather than listed.

  • 1× References added · Oct 15, 2026 – Oct 15, 2026
  • 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

8 on the record

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

  • CVE-2026-99999 ipv4: validate checksum_start before completing checksum 19h
  • CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 19h
  • CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
  • CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
  • CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
  • CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 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-2025-39997 is "ALSA: usb-audio: fix race condition to UAF in snd_usbmidi_free", 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.

Comments

Moderated technical discussion. Read the community guidelines.

No comments yet.

Sign in or create an account to comment and suggest corrections.