CVE-2026-71217

Name	CVE-2026-71217
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.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
iperf3 (PTS)	bullseye	3.9-1+deb11u1	vulnerable
	bullseye (security)	3.9-1+deb11u3	vulnerable
	bookworm	3.12-1+deb12u2	vulnerable
	bookworm (security)	3.12-1+deb12u1	vulnerable
	trixie	3.18-2+deb13u2	vulnerable
	forky, sid	3.20-2.1	vulnerable

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
iperf3	source	(unstable)	(unfixed)

Notes

[trixie] - iperf3 <no-dsa> (Minor issue)
[bookworm] - iperf3 <postponed> (Minor issue)
[bullseye] - iperf3 <postponed> (Minor issue)
https://bugzilla.redhat.com/show_bug.cgi?id=2460984
https://github.com/esnet/iperf/commit/494dd377eca4689672becdf06a85158557db1586