CVE-2026-74497 ALSA: usb-audio: Clamp frame size in implicit-feedback mode
A malicious USB device can cause a denial of service in the Linux kernel by sending oversized sync packets that exceed hardware frame limits.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-74497?
CVE-2026-74497 is a high-severity denial of service vulnerability in Linux, published on 15 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb-audio: Clamp frame size in implicit-feedback mode
snd_usb_handle_sync_urb() scales received sync packet sizes by the sender's stride and stores the result directly in out_packet->packet_size[i]. If a connected USB device sends an oversized sync packet, this frame count can exceed ep->maxframesize.
The un-clamped frame count then propagates to the playback endpoint queue, potentially driving packet transfers beyond the endpoint's hardware frame limits.
Cap the calculated frame count against ep->maxframesize in snd_usb_handle_sync_urb() to prevent oversized packets from entering the playback queue.
Which versions are affected by CVE-2026-74497?
How do I fix CVE-2026-74497?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-74497 being exploited?
There is no known exploitation of CVE-2026-74497 in the wild and no public exploit code.
Sources
Also known as AZL-96488, BELL-CVE-2026-74497, DEBIAN-CVE-2026-74497, GHSA-56rg-f4qq-ghhv, UBUNTU-CVE-2026-74497.