Read the docs
TI-2026-65170 Aliases CVE-2026-101276GHSA-pmgg-x2vj-36cv

Use after free in esnet iperf3

Priority MEDIUM 42CWE-416Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
Present
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-416 and the CVSS impact.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00396 34th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
esnetiperf33.21—No fix listedCNA
  • iperf3 Vendoresnet Affected 3.21 Fixed in — No fix listed CNA

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-101276
  2. 2026-10-03 Alias added: GHSA-pmgg-x2vj-36cv

References

Other 1

  • TI-2026-65296 iperf3 < 3.22 UDP Receive Worker Infinite Loop DoS CVSS 4.0HIGH 8.7
  • TI-2026-65176 Heap-based buffer overflow in esnet iperf3 CVSS 4.0CRITICAL 9.2

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences