==========================================================================
Ubuntu Security Notice USN-7970-1
January 21, 2026

iperf3 vulnerabilities
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 25.10
- Ubuntu 24.04 LTS
- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS

Summary:

Several security issues were fixed in iperf3.

Software Description:
- iperf3: A TCP, UDP, and SCTP network bandwidth measurement tool

Details:

Jorge Sancho Larraz discovered that iperf3 did not properly manage certain
inputs, which could cause the server process to stop responding, waiting
for input on the control connection. A remote attacker could possibly use
this issue to cause a denial of service. This issue was only addressed in
Ubuntu 22.04 LTS. (CVE-2023-7250)

It was discovered that iperf3 had a timing side-channel when performing RSA
decryption. An attacker could possibly use this issue to recover sensitive
information. This issue was only addressed in Ubuntu 20.04 LTS and Ubuntu
22.04 LTS and Ubuntu 24.04 LTS. (CVE-2024-26306)

It was discovered that iperf3 incorrectly handled certain inputs. An
attacker could possibly use this issue to cause a denial of service. This
issue was only addressed in Ubuntu 20.04 LTS, Ubuntu 22.04 LTS and Ubuntu
24.04 LTS. (CVE-2024-53580)

Han Lee discovered that iperf3 had an off-by-one heap overflow. An attacker
could possibly use this issue to crash the program or execute arbitrary
code. This issue was only addressed in Ubuntu 20.04 LTS, Ubuntu 22.04 LTS,
Ubuntu 24.04 LTS and Ubuntu 25.10. (CVE-2025-54349)

Han Lee discovered that iperf3 did not properly manage certain inputs. An
attacker could possibly use this issue to cause a denial of service.
(CVE-2025-54350)

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 25.10
  iperf3                          3.18-2ubuntu0.1
  libiperf0                       3.18-2ubuntu0.1

Ubuntu 24.04 LTS
  iperf3                          3.16-1ubuntu0.1~esm1
                                  Available with Ubuntu Pro
  libiperf0                       3.16-1ubuntu0.1~esm1
                                  Available with Ubuntu Pro

Ubuntu 22.04 LTS
  iperf3                          3.9-1+deb11u1ubuntu0.1
  libiperf0                       3.9-1+deb11u1ubuntu0.1

Ubuntu 20.04 LTS
  iperf3                          3.7-3ubuntu0.1~esm2
                                  Available with Ubuntu Pro
  libiperf0                       3.7-3ubuntu0.1~esm2
                                  Available with Ubuntu Pro

In general, a standard system update will make all the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-7970-1
  CVE-2023-7250, CVE-2024-26306, CVE-2024-53580, CVE-2025-54349,
  CVE-2025-54350

Package Information:
  https://launchpad.net/ubuntu/+source/iperf3/3.18-2ubuntu0.1
  https://launchpad.net/ubuntu/+source/iperf3/3.9-1+deb11u1ubuntu0.1