Remote code execution in a core Windows service (Event Tracing) affects broadly deployed Windows systems and can enable widespread system compromise.
CVE-2026-83874
Heap overflow in Windows Event Tracing allows remote code execution.
Is CVE-2026-83874 being exploited?
Not confirmed. CVE-2026-83874 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 0.77% probability of exploitation in the next 30 days.
How severe is CVE-2026-83874?
CVE-2026-83874 is rated High with a CVSS score of 8.8. 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-2026-83874?
Yes. A fix has been recorded for CVE-2026-83874. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-83874 affect?
CVE-2026-83874 affects Microsoft Windows (Event Tracing / ETW). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-83874?
Apply Microsoft security update immediately; restrict network access to Event Tracing endpoints until patched.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote code execution over the network via crafted Event Tracing input, enabling system compromise and lateral movement.
Immediate action required
- affected>= 10.0.14393.0 and < 10.0.14393.9612
- affected>= 10.0.17763.0 and < 10.0.17763.9376
- affected>= 10.0.19044.0 and < 10.0.19044.7807
- affected>= 10.0.19045.0 and < 10.0.19044.7807
- affected>= 10.0.22631.0 and < 10.0.22631.7652
- affected>= 10.0.22631.0 and < 10.0.22631.7652
- affected>= 10.0.26100.0 and < 10.0.26100.9711
- affected>= 10.0.26200.0 and < 10.0.26200.9711
- affected>= 10.0.28000.0 and < 10.0.28000.3231
- affected>= 10.0.26300.0 and < 10.0.26300.9711
- affected>= 6.2.9200.0 and < 6.2.9200.26434
- affected>= 6.3.9600.0 and < 6.3.9600.23470
- affected>= 6.3.9600.0 and < 6.3.9600.23470
- affected>= 6.2.9200.0 and < 6.2.9200.26434
- affected>= 10.0.14393.0 and < 10.0.14393.9612
- affected>= 10.0.14393.0 and < 10.0.14393.9612
- affected>= 10.0.17763.0 and < 10.0.17763.9376
- affected>= 10.0.17763.0 and < 10.0.17763.9376
- affected>= 10.0.20348.0 and < 10.0.20348.5761
- affected>= 10.0.26100.0 and < 10.0.26100.33650
- affected>= 10.0.26100.0 and < 10.0.26100.33650
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.