Out-of-bounds write in Linux kernel - CVE-2026-74640
Published: August 24, 2026
Vulnerability identifier: #VU144893
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-74640
CWE-ID: CWE-787
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to overwrite kernel memory and cause a denial of service.
The vulnerability exists due to an out-of-bounds write in fcp_meter_ctl_get() when reading ALSA FCP controls with an oversized user-defined meter map. A local user can read a crafted control value to overwrite kernel memory and cause a denial of service.
Installing the oversized meter map requires CAP_SYS_RAWIO, but the created control can later be read by an unprivileged process through /dev/snd/controlC0.
Affected software
Linux kernel
How to mitigate CVE-2026-74640
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3