What’s Vulnerable › Vulnerabilities

CVE-2026-93808: ALSA: usb-audio: caiaq: validate EP1 reply lengths

• Severity: unknown
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-24 · updated 2026-10-03

Description

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.

Affected products

• Linux kernel: 2.6.22 — fixed in 7.2

How to fix

Upgrade to a fixed version: Linux kernel 7.2. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/319393151367e6626affedcdd4f7b7b0286f4246
• https://git.kernel.org/stable/c/74f3c639f64fa5da4e1613149798b5089bce2807
• https://git.kernel.org/stable/c/7cc6b3745a0cea697c8d0684b3094f220281a08d
• https://git.kernel.org/stable/c/91acd231f219452fa58285239f83945accad9513
• https://git.kernel.org/stable/c/aba30af07d4fe499b50209801eba9da8a815522f
• https://git.kernel.org/stable/c/add9328c91c195c494cd68a21b19e5e47a20d784
• https://git.kernel.org/stable/c/af8a172c4f71ac30d625f2966d2389a7fa872819

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