CVE-2026-101308
FreeBSD: TOCTOU race between sound(4) buffer resizing and mmap
FreeBSD FreeBSDOperating systems
CVSS
5.5MediumExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.07%Chance of exploitation activity in the next 30 days, higher than 0% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
What fixes it
No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.
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.
Text from CVE List
Affected versions 3
- FreeBSDaffected: 15.1-RELEASE before p5CVE List
- FreeBSDaffected: 14.5-RELEASE before p2CVE List
- FreeBSDaffected: 14.4-RELEASE before p11CVE List