Use-after-free in FreeBSD - CVE-2026-58091
Published: August 26, 2026
Vulnerability identifier: #VU145748
CSH Severity: Low
CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-58091
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to escalate privileges.
The vulnerability exists due to use-after-free in the SNDCTL_DSP_SYNCSTART ioctl implementation when locking channels in a sync group. A local user can trigger the ioctl on a system with multiple audio devices to escalate privileges.
Systems with zero or one sound devices are unaffected.
Affected software
FreeBSD
How to mitigate CVE-2026-58091
Install security update from vendor's website.