PatchSiren cyber security CVE debrief

CVE-2026-46157 Linux CVE debrief

A data race vulnerability in the Linux kernel's ALSA PCM OSS (Open Sound System) compatibility layer could allow concurrent, unprotected access to the `runtime.oss.trigger` bit field. Because this field is a bit field, unsynchronized writes risk corrupting adjacent bit fields, leading to undefined behavior and potential operational confusion. The issue was discovered through fuzzing. The fix adds `params_lock` mutex protection around accesses to `runtime.oss.trigger` in both `snd_pcm_oss_get_trigger()` and `snd_pcm_oss_poll()`.

Vendor: Linux
Product: Unknown
CVSS: HIGH 7.8
CISA KEV: Not listed in stored evidence
Original CVE published: 2026-05-28
Original CVE updated: 2026-06-09
Advisory published: 2026-05-28
Advisory updated: 2026-06-09

Who should care

Linux system administrators, kernel maintainers, and organizations running workloads with ALSA OSS compatibility enabled, particularly in multi-tenant or high-concurrency audio processing environments

Technical summary

The vulnerability exists in the ALSA (Advanced Linux Sound Architecture) PCM subsystem's OSS compatibility layer. The `runtime.oss.trigger` bit field was accessed without proper synchronization, creating a data race condition. Because bit fields share storage units, concurrent writes to `trigger` could inadvertently modify adjacent bit fields, causing operational confusion. The resolution involves extending the existing `params_lock` mutex coverage to protect read and write operations on `runtime.oss.trigger` in `snd_pcm_oss_get_trigger()` and `snd_pcm_oss_poll()` functions.

Defensive priority

medium

Recommended defensive actions

Apply kernel updates containing the referenced stable commits when available for your distribution
Monitor vendor security advisories for kernel package updates addressing CVE-2026-46157
If running systems with ALSA OSS compatibility enabled, prioritize patching on multi-user or containerized environments where concurrent audio access may occur
Review system logs for unexpected ALSA/OSS-related errors that could indicate trigger state corruption

Evidence notes

The CVE description and kernel commit references confirm this is a data race in ALSA PCM OSS code, resolved by adding mutex protection. Multiple stable kernel branch commits are referenced, indicating backports to supported releases.

Sources and references

Verified primary and authoritative sources

CVE-2026-46157 CVE Program record
Publisher, destination, and source semantics verified

URL: https://www.cve.org/CVERecord?id=CVE-2026-46157

CVE Program - Official CVE Program record with source-provided CVE metadata.
CVE-2026-46157 NVD vulnerability detail
Publisher, destination, and source semantics verified

URL: https://nvd.nist.gov/vuln/detail/CVE-2026-46157

NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Source reference
Unverified legacy reference

URL: https://git.kernel.org/stable/c/49f9d048845be874df7997e4b1ce662de450c4b6

416baaa9-dc9f-4396-8d5f-8c081fb06d67
Source reference
Unverified legacy reference

URL: https://git.kernel.org/stable/c/6b01c1bc9a4748ab37548a700a8aaff910e298e6

416baaa9-dc9f-4396-8d5f-8c081fb06d67
Source reference
Unverified legacy reference

URL: https://git.kernel.org/stable/c/901ac0ff15edf9503162e2cf6579bd11a30f1ed4

416baaa9-dc9f-4396-8d5f-8c081fb06d67
Source reference
Unverified legacy reference

URL: https://git.kernel.org/stable/c/ac3e9b55b7da6f0be51720bd330a0edc1a8b61f1

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.