Description
A flaw was found in iperf3. A remote attacker can exploit this vulnerability by sending crafted control-channel JSON with oversized numeric parameters, such as `parallel` and `len`, which are not properly validated by the server. This improper input validation can lead to excessive stream and thread creation, as well as large buffer allocations, causing resource exhaustion. Consequently, this can result in a Denial of Service (DoS) on the affected iperf3 server.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | — | — |
| Red Hat | Red Hat Enterprise Linux 8 | — | — |
| Red Hat | Red Hat Enterprise Linux 9 | — | — |
| Red Hat | Red Hat Enterprise Linux 7 | — | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | iperf3 | 3.22-0.1 | — |
| Debian 13 | iperf3 | No fix yet | — |
| Debian 12 | iperf3 | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | iperf3 | No fix yet | — |
| Ubuntu 26.04 LTS | iperf3 | No fix yet | — |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 24.04 LTS | iperf3 | No fix yet | — |
| Ubuntu Pro 22.04 LTS | iperf3 | No fix yet | — |
| Ubuntu Pro 20.04 LTS | iperf3 | No fix yet | — |
| Ubuntu Pro 18.04 LTS | iperf3 | No fix yet | — |
| Ubuntu Pro 16.04 LTS | iperf3 | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | iperf3 | 3.17.1-6.el10_2.1 | RHSA-2026:61680 |
| RHEL 9 | iperf3 | 3.9-17.el9_8.1 | RHSA-2026:61389 |
| RHEL 8 | iperf3 | 3.5-12.el8_10.1 | RHSA-2026:61257 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | iperf3 | 3.17.1-6.el10_2.1 | ALSA-2026:61680 |
| AlmaLinux 9 | iperf3 | 3.9-17.el9_8.1 | ALSA-2026:61389 |
| AlmaLinux 8 | iperf3 | 3.5-12.el8_10.1 | ALSA-2026:61257 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | iperf3 | 3.17.1-6.el10_2.1 | RLSA-2026:61680 |
| Rocky Linux 9 | iperf3 | 3.9-17.el9_8.1 | RLSA-2026:61389 |
| Rocky Linux 8 | iperf3 | 3.5-12.el8_10.1 | RLSA-2026:61257 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | iperf | 3.22-150000.3.18.1 | SUSE-SU-2026:4678-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | iperf | 3.21-160000.1.1 | SUSE-SU-2026:24234-1 |
| SLES 16.0 | iperf | 3.21-160000.1.1 | SUSE-SU-2026:24234-1 |
| SLE Micro 6.2 | iperf | 3.21-160000.1.1 | SUSE-SU-2026:24178-1 |
| SUSE Enterprise Storage 7.1 | iperf | 3.22-150000.3.18.1 | SUSE-SU-2026:4678-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | iperf | 3.22-1.1 | openSUSE-SU-2026:12060-1 |
| openSUSE Leap 16.0 | iperf | 3.21-160000.1.1 | openSUSE-SU-2026:22090-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | iperf3 +1 | 3.19.1-1.amzn2023.0.1 | ALAS2023-2026-2070 |
| Amazon Linux 2 | iperf3 +1 | 3.1.7-2.amzn2.0.6 | ALAS2-2026-3869 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | iperf3 | 3.17.1-5 | — |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
GitHub 1 repository
-
Reelix/CVE-2026-71217-PoC ★ 0 · Sep 20, 2026
A PoC for CVE-2026-71217
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 17
- RHSA-2026:61680 Red Hat Security Advisory: iperf3 security update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- ALSA-2026:61389 Important: iperf3 security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:61680 Important: iperf3 security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:61257 Important: iperf3 security update AlmaLinux Security Advisories · Oct 29, 2026
- SUSE-SU-2026:24234-1 Security update for iperf SUSE / openSUSE Security Updates · Oct 21, 2026
- WID-SEC-2026-3080 Red Hat Enterprise Linux (iperf3): Schwachstelle ermöglicht Denial of Service BSI CERT-Bund (WID) · Oct 20, 2026
- SUSE-SU-2026:24178-1 Security update for iperf SUSE / openSUSE Security Updates · Oct 20, 2026
- openSUSE-SU-2026:22090-1 Security update for iperf SUSE / openSUSE Security Updates · Oct 19, 2026
- SUSE-SU-2026:4678-1 Security update for iperf SUSE / openSUSE Security Updates · Oct 15, 2026
- openSUSE-SU-2026:12060-1 iperf-3.22-1.1 on GA media SUSE / openSUSE Security Updates · Oct 6, 2026
- RLSA-2026:61680 Important: iperf3 security update Rocky Linux Security Advisories · Sep 1, 2026
- RHSA-2026:61389 Red Hat Security Advisory: iperf3 security update Red Hat Security Advisories (RHSA) · Sep 1, 2026
- RHSA-2026:61257 Red Hat Security Advisory: iperf3 security update Red Hat Security Advisories (RHSA) · Sep 1, 2026
- RLSA-2026:61389 Important: iperf3 security update Rocky Linux Security Advisories · Sep 1, 2026
- ALAS2-2026-3869 Important: iperf3 security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Aug 31, 2026
- RLSA-2026:61257 Important: iperf3 security update Rocky Linux Security Advisories · Aug 31, 2026
- ALAS2023-2026-2070 Important: iperf3 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Aug 31, 2026
References
- RHSA-2026:61257 vendor-advisory
- RHSA-2026:61389 vendor-advisory
- RHSA-2026:61680 vendor-advisory
- https://access.redhat.com/security/cve/CVE-2026-71217 vdb-entry
- RHBZ#2460984 issue-tracking
- https://github.com/esnet/iperf/commit/494dd377eca4689672becdf06a85158557db1586