CVE-2026-58091
Kernel use-after-free via the SNDCTL_DSP_SYNCSTART ioctl
The implementation of this ioctl attempts to acquire locks on all channels in a sync group. If locking a channel would block, it releases the sync group list lock and sleeps. Upon reawakening, it is possible that the sync group structure is freed, but the implementation did not handle this possibility.
On a system with a multiple audio devices, an unprivileged local user can exploit this use-after-free to escalate privileges.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Kernel use-after-free via the SNDCTL_DSP_SYNCSTART ioctl
The implementation of this ioctl attempts to acquire locks on all channels in a sync group. If locking a channel would block, it releases the sync group list lock and sleeps. Upon reawakening, it is possible that the sync group structure is freed, but the implementation did not handle this possibility.
On a system with a multiple audio devices, an unprivileged local user can exploit this use-after-free to escalate privileges.
- Record
CVE-2026-58091- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-416
- Updated
- 2026-11-02
EUVDEUVD-2026-66236
The implementation of this ioctl attempts to acquire locks on all channels in a sync group. If locking a channel would block, it releases the sync group list lock and sleeps. Upon reawakening, it is possible that the sync group structure is freed, but the implementation did not handle this possibility.
On a system with a multiple audio devices, an unprivileged local user can exploit this use-after-free to escalate privileges.
- Record
EUVD-2026-66236- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
NVD
The implementation of this ioctl attempts to acquire locks on all channels in a sync group. If locking a channel would block, it releases the sync group list lock and sleeps. Upon reawakening, it is possible that the sync group structure is freed, but the implementation did not handle this possibility.
On a system with a multiple audio devices, an unprivileged local user can exploit this use-after-free to escalate privileges.
- Record
CVE-2026-58091- CVSS 3.1
- 7.8 High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-416
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-58091 is a high vulnerability (CVSS 7.8) in Freebsd, published August 26, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.15%, the 4th percentile. No source names a fixed version.