A file descriptor can be closed while a thread is blocked in a poll(2) or select(2) call waiting for that descriptor. Because the blocked thread does not hold a reference to the underlying object, this closure may result in the object being freed while the thread remains blocked. In this situation, the kernel must remove the blocked thread from the per-object wait queue prior to freeing the object.
In the case of some file descriptor types, the kernel failed to unlink blocked threads from the object before freeing it. When the blocked thread is subsequently woken, it accesses memory that has already been freed resulting in a use-after-free vulnerability.
The use-after-free vulnerability may be triggered by an unprivileged local user and can be exploited to obtain superuser privileges.
References
| Link | Resource |
|---|---|
| https://security.freebsd.org/advisories/FreeBSD-SA-26:19.file.asc | Vendor Advisory |
Configurations
Configuration 1 (hide)
|
History
21 May 2026, 19:01
| Type | Values Removed | Values Added |
|---|---|---|
| CPE | cpe:2.3:o:freebsd:freebsd:15.0:p5:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:14.3:p6:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:15.0:p7:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:15.0:-:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:14.3:-:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:14.3:p4:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:15.0:p4:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:14.3:p3:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:14.3:p2:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:14.3:p9:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:14.3:p7:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:15.0:p6:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:15.0:p2:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:14.4:-:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:14.3:p8:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:14.4:p3:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:14.4:p4:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:14.4:rc1:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:14.3:p13:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:14.3:p5:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:15.0:p8:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:14.3:p11:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:14.3:p1:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:15.0:p3:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:14.3:p10:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:14.4:p2:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:15.0:p1:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:14.4:p1:*:*:*:*:*:* cpe:2.3:o:freebsd:freebsd:14.3:p12:*:*:*:*:*:* |
|
| First Time |
Freebsd
Freebsd freebsd |
|
| References | () https://security.freebsd.org/advisories/FreeBSD-SA-26:19.file.asc - Vendor Advisory |
21 May 2026, 15:16
| Type | Values Removed | Values Added |
|---|---|---|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 7.8 |
21 May 2026, 10:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-05-21 10:16
Updated : 2026-05-21 19:01
NVD link : CVE-2026-45251
Mitre link : CVE-2026-45251
CVE.ORG link : CVE-2026-45251
JSON object : View
Products Affected
freebsd
- freebsd
CWE
CWE-416
Use After Free