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CVE-2026-58083

8.4
High
EPSS 0.12%Patch availableAug 19, 2026

Local kernel use-after-free in kqueue copy during fork enabling privilege escalation

common questions

Is CVE-2026-58083 being exploited?

Not confirmed. CVE-2026-58083 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.12% probability of exploitation in the next 30 days.

How severe is CVE-2026-58083?

CVE-2026-58083 is rated High with a CVSS score of 8.4. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.

Is there a patch for CVE-2026-58083?

Yes. A fix has been recorded for CVE-2026-58083. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.

What does CVE-2026-58083 affect?

CVE-2026-58083 affects Kernels implementing kqueue/knote (FreeBSD), NetBSD, OpenBSD, macOS. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.

What should I do about CVE-2026-58083?

Apply vendor kernel updates when released; restrict untrusted local accounts; monitor for privilege escalations.

Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.

executive summary
technical analysis
affected
Kernels implementing kqueue/knote (FreeBSD)NetBSDOpenBSDmacOS
impact

An unprivileged local user can trigger a kernel use-after-free during fork to escalate privileges to root.

action required

Patch when possible

affected versions
FreeBSD FreeBSD
  • affected>= 15.1-RELEASE and < p2

As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.

how to fix
Remediation steps are tailored for users whose stack is affected. Add this technology to your stack to see the fix checklist.
references
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