CVE-2026-74498 ALSA: usb-audio: Fix DMA buffer out-of-bounds write when fill_max is set
A USB audio driver flaw allows heap memory corruption via DMA, potentially enabling local privilege escalation or code execution.
- 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-2026-74498?
CVE-2026-74498 is a memory corruption 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: Fix DMA buffer out-of-bounds write when fill_max is set
When a USB audio endpoint requests full packet transfers via the fill_max descriptor flag, data_ep_set_params() promotes ep->curpacksize to ep->maxpacksize. However, maxsize is left at the original sample-rate derived value.
Since u->buffer_size is allocated as maxsize * packets, the resulting DMA buffer is far too small for the requested transfer length. When the USB host controller streams up to curpacksize bytes per packet, it writes past the end of the buffer via DMA, corrupting kernel heap memory.
Update maxsize to curpacksize when fill_max is set so that the allocated DMA buffer size matches the actual transfer request size.
[ changed to reassign maxsize only when ep->fill_max is set -- tiwai ]
Which versions are affected by CVE-2026-74498?
How do I fix CVE-2026-74498?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-74498 being exploited?
There is no known exploitation of CVE-2026-74498 in the wild and no public exploit code.
Sources
Also known as AZL-96519, BELL-CVE-2026-74498, DEBIAN-CVE-2026-74498, GHSA-ppm8-hvcv-5jfx, UBUNTU-CVE-2026-74498.