CVE-2026-98769 usb: gadget: f_uac1_legacy: validate bRequest index in generic_{set,get}_cmd
A malicious USB host can trigger out-of-bounds memory access in the Linux kernel USB audio gadget driver, potentially leading to code execution or privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-98769?
CVE-2026-98769 is a memory corruption vulnerability in Linux, published on 18 Oct 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_uac1_legacy: validate bRequest index in generic_{set,get}_cmd
generic_set_cmd() and generic_get_cmd() use the low nibble of ctrl->bRequest as an index into con->data[]:
u8 cmd = (ctrl->bRequest & 0x0F); /* 0 .. 15 */ ... con->data[cmd] = value; /* OOB when cmd >= 5 */
struct usb_audio_control (include/linux/usb/audio.h) declares data as a 5-element array, so indices 5 through 15 write (or read) up to 44 bytes past the end of the array on the heap.
A malicious USB host can craft a class-specific SET_CUR / GET_CUR request with an arbitrary bRequest value, triggering the out-of-bounds access from an IRQ completion handler with no further preconditions.
Add an ARRAY_SIZE() guard to both functions.
Which versions are affected by CVE-2026-98769?
How do I fix CVE-2026-98769?
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-2026-98769 being exploited?
There is no known exploitation of CVE-2026-98769 in the wild and no public exploit code.
Sources
Also known as AZL-108996, BELL-CVE-2026-98769, DEBIAN-CVE-2026-98769, GHSA-m6wv-vgq8-7pqj, UBUNTU-CVE-2026-98769.