CVE-2026-71218

Name	CVE-2026-71218
Description	A flaw was found in iperf3. A remote unauthenticated attacker can exploit a vulnerability in the `JSON_read()` function, which accepts a peer-controlled message length and allocates memory without an upper bound. This allows the attacker to trigger excessive memory consumption, leading to a Denial of Service (DoS) through memory exhaustion, severe slowdown, or termination of the iperf3 service.
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	fixed
	forky, sid	3.20-2.1	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
iperf3	source	(unstable)	3.18-1

Notes

[bookworm] - iperf3 <postponed> (Minor issue)
[bullseye] - iperf3 <postponed> (Minor issue)
https://github.com/esnet/iperf/commit/0128d0357b7e8916fe39e980e455729bc0e5fd4e (3.18)
https://bugzilla.redhat.com/show_bug.cgi?id=2463003