CVE intelligence

CVE-2026-101276

Vulnerability intelligence

Published Sep 30, 2026Sources checked Oct 4, 2026

9.2CRITICALCVSS out of 10

What this means

Review the available evidence

CVE-2026-101276 and is rated Critical severity with a CVSS score of 9.2. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Microsoft Security Response Center guidance

Release Notes

CISA KEVNot listedBased on the latest collected catalog

EPSS0.4%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-101276?

iperf3 3.21 (esnet/iperf) contains a remote, unauthenticated heap use-after-free: the server's per-test watchdog server_timer_proc() frees streams without cancelling/joining their worker threads, so a blocked worker dereferences a freed iperf_stream; fixed in 3.22.