SB2026082639 - Privilege escalation in FreeBSD SNDCTL_DSP_SYNCSTART ioctl implementation
Published: August 26, 2026
Security Bulletin ID
SB2026082639
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Code execution
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Use-after-free (CVE-ID: CVE-2026-58091)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 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]
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.
Remediation
Install update from vendor's website.