---
id: CVE-2026-93808
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ALSA: usb-audio: caiaq: validate EP1 reply lengths

  usb_ep1_command_reply_dispatch() uses buf[0] as a command byte and then
  reads command-specific fixed items from the …
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ALSA: usb-audio: caiaq: validate EP1 reply lengths

  usb_ep1_command_reply_dispatch() uses buf[0] as a command byte and then
  reads command-specific fixed items from the …
severity: medium
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 523f1dce37434a9a6623bf46e7893e2b4b10ac3c <
    91acd231f219452fa58285239f83945accad9513
  - >-
    Linux >= 523f1dce37434a9a6623bf46e7893e2b4b10ac3c <
    7cc6b3745a0cea697c8d0684b3094f220281a08d
  - >-
    Linux >= 523f1dce37434a9a6623bf46e7893e2b4b10ac3c <
    add9328c91c195c494cd68a21b19e5e47a20d784
  - >-
    Linux >= 523f1dce37434a9a6623bf46e7893e2b4b10ac3c <
    319393151367e6626affedcdd4f7b7b0286f4246
  - >-
    Linux >= 523f1dce37434a9a6623bf46e7893e2b4b10ac3c <
    af8a172c4f71ac30d625f2966d2389a7fa872819
  - >-
    Linux >= 523f1dce37434a9a6623bf46e7893e2b4b10ac3c <
    74f3c639f64fa5da4e1613149798b5089bce2807
  - >-
    Linux >= 523f1dce37434a9a6623bf46e7893e2b4b10ac3c <
    aba30af07d4fe499b50209801eba9da8a815522f
  - Linux 2.6.22
published: '2026-09-24'
updated: '2026-10-03'
sourceUpdated: '2026-10-03T11:17:50.603'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-93808'
references:
  - url: 'https://git.kernel.org/stable/c/319393151367e6626affedcdd4f7b7b0286f4246'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/74f3c639f64fa5da4e1613149798b5089bce2807'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/7cc6b3745a0cea697c8d0684b3094f220281a08d'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/91acd231f219452fa58285239f83945accad9513'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/aba30af07d4fe499b50209801eba9da8a815522f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/add9328c91c195c494cd68a21b19e5e47a20d784'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/af8a172c4f71ac30d625f2966d2389a7fa872819'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-93808.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-93808'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2540451'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-93808'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-93808'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-93808.mbox
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00173
epssPercentile: 0.06618
ingestedAt: '2026-09-24T16:47:15.896Z'
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe:
  - CWE-125
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

ALSA: usb-audio: caiaq: validate EP1 reply lengths

usb_ep1_command_reply_dispatch() uses buf[0] as a command byte and then
reads command-specific fixed items from the same URB buffer. Several
paths use buf + 1, buf[1], buf[2], or buf + 3 without first proving that
urb->actual_length contains those bytes.

Add per-command length checks, use a payload length derived from the
bytes after the command byte for the control-state copy, and reject short
analog input payloads before the input helper reads fixed offsets from
the EP1 reply.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-10-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-93808.json)