Bug 2544367 (CVE-2026-101276)

Summary: CVE-2026-101276 iperf3: iperf3: heap use-after-free in server watchdog timer
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: high    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers, yguenane
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in iperf3. A heap use-after-free vulnerability—a condition where memory is accessed after being released—occurs when the server watchdog timer prematurely frees stream resources without first terminating active worker threads. A remote, unauthenticated attacker could trigger this timing flaw during a test to corrupt memory, potentially leading to arbitrary code execution or crashing the server to cause a Denial of Service (DoS).
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-09-30 21:24:44 UTC 
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.