CVE-2026-58086: Freebsd

High severity, CVSS 8.1. EPSS: 0.4% chance of exploitation in the next 30 days.

As an inadvertent side effect of an unrelated code change, PRIV_KTRACE was always denied to a jailed root user. Tracing configured by a jailed root user was therefore not flagged as privileged. An unprivileged user in a jail that has permission to debug the target process can modify the jailed root user's ktrace(2) flags, or disable tracing outright. A jailed root user therefore cannot reliably trace unprivileged processes.

Affected products

• Freebsd Freebsd: version 15.0 only; version 15.1 only

Published 2026-08-19. Last modified 2026-08-31.