Vulnerability · Published Oct 15, 2026 · Assigned by freebsd
CVE-2026-101308TOCTOU race between sound(4) buffer resizing and mmap
Medium 5.5
In plain English
A medium-severity security flaw in FreeBSD from FreeBSD. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 0% of all known vulnerabilities).
Official description
When an audio channel's buffer needs to be resized, the sound(4) driver checks that the buffer is not memory-mapped and then drops the channel lock to allocate a new buffer. An mmap(2) call on another thread can complete during this window, after which the resize path frees the now-mapped buffer without rechecking. An unprivileged local user with access to a sound device can exploit this race to trigger a use-after-free in the kernel, potentially escalating privileges.
Affected products (as reported)
Weakness: CWE-367 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H