CVE-2026-58083

HIGH
MEDIUM Priority: 0.01 BB Relevance: 52/100
Published: 2026-08-19 Modified: 2026-10-27 First seen: 2026-10-29 Status: active

Attack Surface

Low Complexity No Auth No Interaction Conf. Impact Integ. Impact

CVSS Vector Breakdown

AV: Local
AC: Low
PR: None
UI: None
S: Unchanged
C: High
I: High
A: High

Description

While the kernel was copying knotes during fork, a knote with a timer-based filter could fire and be enqueued on the kqueue's active list before the copy was complete. The copy routine did not account for this and could enqueue the new knote a second time, corrupting the active list. In addition, the copy routine did not hold the appropriate locks while reading knote state, allowing further races. An unprivileged local user can trigger a use-after-free in the kernel, potentially leading to privilege escalation.

Weakness Classification (1)

Affected Software (4)

VendorProductVersion
freebsd freebsd 15.1
freebsd freebsd 15.1
freebsd freebsd 15.1
freebsd freebsd 15.1

References & Advisories (1)

Bug Bounty Relevance

52 / 100
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

8.4 / 10.0 v3.1
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploitation Probability

0.17%
Raw Score 0.001680
Percentile 6.0%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00168
2026-10-28
0.00168

Intelligence Sources

nvd ref →