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CVE-2026-90032 Linux CVE debrief

A use-after-free vulnerability exists in the Linux kernel's media subsystem, specifically in the usbtv driver. When an ALSA card is closed, the usbtv device may be freed prematurely, leading to a potential crash or code execution when the ALSA card is later accessed. This issue arises because the ALSA PCM callbacks store the driver state in pcm->private_data, which can outlive USB disconnect. The disconnect path can then drop the V4L2 device reference and free struct usbtv before ALSA releases the substream. To address this, it is essential to keep the usbtv device alive while the ALSA card exists, ensuring that the device is not prematurely freed.

Vendor
Linux
Product
Unknown
CVSS
HIGH 7.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-09-16
Original CVE updated
2026-10-19
Advisory published
2026-09-16
Advisory updated
2026-10-19

Who should care

Linux kernel developers, Linux distribution maintainers, and users of Linux systems with the usbtv driver installed should assess exposure and verify that their systems are updated with the provided patches.

Why it matters

The CVE-2026-90032 vulnerability in the Linux kernel's usbtv driver requires attention from Linux kernel developers, distribution maintainers, and users to assess exposure and apply patches to prevent potential system crashes or code execution.

  • Potential system crashes or code execution due to use-after-free vulnerability
  • Need to verify Linux kernel version and apply patches to prevent exploitation
  • Possible data corruption or loss due to improper device handling

Technical summary

The Linux kernel's media subsystem, specifically the usbtv driver, has a use-after-free vulnerability. The ALSA PCM callbacks store the driver state in pcm->private_data, which can outlive USB disconnect. The disconnect path can then drop the V4L2 device reference and free struct usbtv before ALSA releases the substream, leading to a potential crash or code execution when the ALSA card is later accessed.

Defensive priority

High

Recommended defensive actions

  • Review and apply the provided patches to ensure the usbtv device is kept alive while the ALSA card exists.
  • Verify that the Linux kernel is updated to a version that includes the fix.
  • Monitor system logs for potential crashes or errors related to the usbtv driver.
  • Perform a thorough review of system configurations and apply necessary patches.
  • Check for any exposed systems and prioritize patching based on risk assessment.
  • Implement compensating controls for exposed systems while remediation is scheduled.
  • Track the status of remediation efforts and verify successful patch application.

Evidence notes

The vulnerability is caused by the ALSA PCM callbacks storing the driver state in pcm->private_data, which can outlive USB disconnect. The disconnect path can then drop the V4L2 device reference and free struct usbtv before ALSA releases the substream.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-90032 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-90032

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-90032 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-90032

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

Supplemental references

  • media: usbtv: keep device alive while ALSA card exists

    Unverified legacy reference

    URL: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/90xxx/CVE-2026-90032.json

    cve_program_cvelist_v5

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/97b5e8b22b98e287481a97a9a4cfebbb348738a5

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/503be26ff888cb3576e55d251895d290e8146f27

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/be0f7745f883386e5263b4e475686a81dfa87175

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/67374e3a00814dcdd46e9feca61f69f7f2d81957

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/239d1683e08b2aee2a15ef35706e1ea9a76681d8

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/7690a86b193271322cd31ab77349a87aa10858e4

    Supplemental source

  • Source reference

    Unverified legacy reference

    URL: https://git.kernel.org/stable/c/1618257cb0aba4ce342ae8c0228368c24161f5fb

    Supplemental source

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.