CVE-2026-70455

Name	CVE-2026-70455
Description	rsync 3.4.2 before 3.5.0 contains a denial of service vulnerability that allows a remote sender to exhaust system resources by specifying the --zt short alias for --compress-threads, which bypasses the refuse options directive's string matching on long option names. Attackers can specify --zt=N with a large value to spawn an unbounded number of Zstandard worker threads on the receiver, exhausting available thread and memory resources.
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
rsync (PTS)	bookworm	3.2.7-1+deb12u6	vulnerable
	bookworm (security)	3.2.7-1+deb12u5	vulnerable
	trixie	3.4.1+ds1-5+deb13u4	vulnerable
	trixie (security)	3.4.1+ds1-5+deb13u3	vulnerable
	forky, sid	3.5.0+ds1-2	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
rsync	source	(unstable)	3.5.0+ds1-1

https://download.samba.org/pub/rsync/NEWS#3.5.0