Vulnerabilities

Vulnerability · CVE-2026-43437

In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: fix use-after-free on linked stream runtime in snd_pcm_drain() In the drain loop, the lo…

Published May 8, 2026 · catalog updated Sep 2, 2026 · linux kernel

Check if you run it

No confirmed exploitation is on record for CVE-2026-43437. EPSS is 0.13%. Act only if a listed version of linux kernel is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.8
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.13%
Remediation
Advisory link
Affected products
cpe linux/linux kernel

In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: fix use-after-free on linked stream runtime in snd_pcm_drain() In the drain loop, the local variable 'runtime' is reassigned to a linked stream's runtime (runtime = s->runtime at line 2157). After releasing the stream lock at line 2169, the code accesses runtime->no_period_wakeup, runtime->rate, and runtime->buffer_size (lines 2170-2178) — all referencing the linked stream's runtime without any lock or refcount protecting its lifetime. A concurrent close() on the linked stream's fd triggers snd_pcm_release_substream() → snd_pcm_drop() → pcm_release_private() → snd_pcm_unlink() → snd_pcm_detach_substream() → kfree(runtime). No synchronization prevents kfree(runtime) from completing while the drain path dereferences the stale pointer. Fix by caching the needed runtime fields (no_period_wakeup, rate, buffer_size) into local variables while still holding the stream lock, and using the cached values after the lock is released.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe linux/linux kernel7.0

How to fix CVE-2026-43437

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-43437. EPSS is 0.13%. Act only if a listed version of linux kernel is installed.

Which versions are affected?

Compare what you have installed with linux/linux kernel 7.0. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-416: Use After Free. EPSS 0.13%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. May 8, 2026 · NIST NVD

    Detected

    In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: fix use-after-free on linked stream runtime in snd_pcm_drain() In the drain loop, the local variable 'runtime' is reassigned to a linked stream's runtime (runtime = s->runtime at line 2157). After releasing the stream lock at line 2169, the code accesses runtime->no_period_wakeup, runtime->rate, and runtime->buffer_size

  2. Sep 2, 2026 · NIST NVD

    Updated

    In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: fix use-after-free on linked stream runtime in snd_pcm_drain() In the drain loop, the local variable 'runtime' is reassigned to a linked stream's runtime (runtime = s->runtime at line 2157). After releasing the stream lock at line 2169, the code accesses runtime->no_period_wakeup, runtime->rate, and runtime->buffer_size

Sources

  • CVE.orgVulnerability recordCVE-2026-43437

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-43437

    30-day exploitation probability 0.1%

    first.org
  • NIST NVDVulnerability recordCVE-2026-43437

    In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: fix use-after-free on linked stream runtime in snd_pcm_drain() In the drain loop, the local variable 'runtime' is reassigned to a linked stream's runtime (runtime = s->runtime at line 2157). After r

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.