Vulnerability · Published Aug 19, 2026 · Assigned by freebsd

CVE-2026-58086ktrace(2) privilege incorrectly validated in jails

High 8.1

In plain English

A high-severity security flaw in FreeBSD from FreeBSD. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 32% of all known vulnerabilities).

Severity (CVSS 3.1)8.1High

Exploit odds (30 days)0.4%top 68.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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 (as reported)

Vendor	Product	Versions
FreeBSD	FreeBSD	15.1-RELEASE – before p215.0-RELEASE – before p12

Weakness: CWE-273 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H

References

https://security.freebsd.org/advisories/FreeBSD-SA-26:53.ktrace.asc vendor-advisory