CVE-2026-58091
Kernel use-after-free via the SNDCTL_DSP_SYNCSTART ioctl
Description
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.
INFO
Published Date :
Aug. 26, 2026, 5:18 a.m.
Last Modified :
Sept. 24, 2026, 1:55 p.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Acquire locks carefully to avoid race conditions.
- Ensure sync group structure is valid after waking.
- Apply relevant security patches from the vendor.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-58091.
| URL | Resource |
|---|---|
| https://security.freebsd.org/advisories/FreeBSD-SA-26:58.sound.asc | Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-58091 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-58091
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-58091 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-58091 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Sep. 24, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:o:freebsd:freebsd:15.0:p1:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:15.0:p2:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:15.0:p3:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:15.0:p4:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:14.4:p1:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:14.4:p2:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:15.0:p5:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:15.0:p6:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:14.4:p3:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:14.4:p4:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:15.0:p7:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:15.0:p8:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:14.4:p5:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:15.0:p9:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:14.4:p6:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:14.4:p7:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:15.0:p10:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:15.0:p11:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:15.1:p1:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:15.1:p2:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:14.4:p8:*:*:*:*:*:* *cpe:2.3:o:freebsd:freebsd:15.0:p12:*:*:*:*:*:* Added Reference Type FreeBSD: https://security.freebsd.org/advisories/FreeBSD-SA-26:58.sound.asc Types: Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 27, 2026
Action Type Old Value New Value Changed SSVC {'id': 'CVE-2026-58091', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-26T15:25:46.730587Z'} {'id': 'CVE-2026-58091', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-26T00:00:00+00:00'} -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 26, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Added SSVC {'id': 'CVE-2026-58091', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-26T15:25:46.730587Z'} -
New CVE Received by [email protected]
Aug. 26, 2026
Action Type Old Value New Value Added Description 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. Added CWE CWE-416 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/58xxx/CVE-2026-58091.json">CVE-2026-58091</a> Added Reference https://security.freebsd.org/advisories/FreeBSD-SA-26:58.sound.asc