Read the docs

Heap-based buffer overflow in esnet iperf3

Priority MEDIUM 42CWE-122Published · 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-122 and the CVSS impact.

Summary

iperf3 3.20–3.21 (esnet/iperf) has a pre-auth heap buffer overflow in decrypt_rsa_message(): a 256-byte RSA buffer is BIO_read with the attacker-controlled ciphertext length (guard warns only), so an unauthenticated client overflows the heap via an oversized authtoken; fixed in 3.22

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00383 32nd 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
esnetiperf33.20; 3.21—No fix listedCNA
  • iperf3 Vendoresnet Affected 3.20; 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-2026-101283
  2. 2026-10-03 Alias added: GHSA-pwcx-5qh6-2pxc

References

  • TI-2026-65296 iperf3 < 3.22 UDP Receive Worker Infinite Loop DoS CVSS 4.0HIGH 8.7
  • TI-2026-65170 Use after free in esnet iperf3 CVSS 4.0CRITICAL 9.2

Sources