CVE-2026-58099

When copying knotes from a parent kqueue to a child, the copy code did not correctly exclude marker knotes (used internally to track list traversal position) before marking them as in-flux and releasing the kqueue lock. If another thread freed a marker while the lock was dropped, the subsequent in-flux decrement operated on freed memory. An unprivileged local user may be able to exploit these races to escalate privileges.

CVSS v3 7.0 HIGH

7.0^/10

CVSS v3 : HIGH

Vector :

Exploitability : 1.0 / Impact : 5.9

Attack Vector LOCAL

Attack Complexity HIGH

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://security.freebsd.org/advisories/FreeBSD-SA-26:65.kqueue.asc	Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:o:freebsd:freebsd:15.1:-::::::
	cpe:2.3:o:freebsd:freebsd:15.1:p1::::::
	cpe:2.3:o:freebsd:freebsd:15.1:p2::::::
	cpe:2.3:o:freebsd:freebsd:15.1:p3::::::

History

19 Oct 2026, 21:02

Type	Values Removed	Values Added
CPE		cpe:2.3:o:freebsd:freebsd:15.1:-:::::: cpe:2.3:o:freebsd:freebsd:15.1:p1:::::: cpe:2.3:o:freebsd:freebsd:15.1:p3:::::: cpe:2.3:o:freebsd:freebsd:15.1:p2::::::
First Time		Freebsd freebsd Freebsd
References	~~() https://security.freebsd.org/advisories/FreeBSD-SA-26:65.kqueue.asc -~~	() https://security.freebsd.org/advisories/FreeBSD-SA-26:65.kqueue.asc - Vendor Advisory

19 Oct 2026, 15:17

Type	Values Removed	Values Added
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 7.0

15 Oct 2026, 07:18

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-15 07:18

Updated : 2026-10-19 21:02

NVD link : CVE-2026-58099

Mitre link : CVE-2026-58099

CVE.ORG link : CVE-2026-58099

JSON object : View

Products Affected

freebsd

freebsd

CWE

CWE-362

Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CWE-416

Use After Free

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