CVE-2026-5438

Name	CVE-2026-5438
Description	A gzip decompression bomb vulnerability exists when Orthanc processes HTTP request with `Content-Encoding: gzip`. The server does not enforce limits on decompressed size and allocates memory based on attacker-controlled compression metadata. A specially crafted gzip payload can trigger excessive memory allocation and exhaust system memory.
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)
Debian Bugs	1133182

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
orthanc (PTS)	bullseye	1.9.2+really1.9.1+dfsg-1+deb11u1	vulnerable
	bullseye (security)	1.9.2+really1.9.1+dfsg-1+deb11u2	vulnerable
	bookworm, bookworm (security)	1.10.1+dfsg-2+deb12u1	vulnerable
	trixie	1.12.7+dfsg-4	vulnerable
	forky	1.12.11+dfsg-4	fixed
	sid	1.12.11+dfsg-6	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
orthanc	source	(unstable)	1.12.10+dfsg-4			1133182

https://kb.cert.org/vuls/id/536588
https://orthanc.uclouvain.be/hg/orthanc/rev/5ce108190752