{"id":"DEBIAN-CVE-2026-117556","details":"zchunk before 1.5.5 contains a heap out-of-bounds read vulnerability in read_preface() in src/lib/header.c that passes the total header length instead of remaining bytes to compint parsing functions. Attackers can supply a crafted .zck file whose header ends inside a compressed integer, causing reads past the heap header buffer and crashing the application.","modified":"2026-10-29T10:00:17.148990222Z","published":"2026-10-27T14:16:36.340Z","upstream":["CVE-2026-117556"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-117556"}],"affected":[{"package":{"name":"zchunk","ecosystem":"Debian:12","purl":"pkg:deb/debian/zchunk?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.2.3+ds1-2","1.3.0+ds1-0.1","1.3.1+ds1-1","1.3.1+ds1-1~bpo12+1","1.3.2+ds1-1","1.4.0+ds1-1","1.5.1+ds1-1","1.5.1+ds1-1~bpo12+1","1.5.2+ds1-1","1.5.2+ds1-2","1.5.3+ds1-1","1.5.3+ds1-2"],"ecosystem_specific":{"urgency":"unimportant"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-117556.json"}},{"package":{"name":"zchunk","ecosystem":"Debian:13","purl":"pkg:deb/debian/zchunk?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.5.1+ds1-1","1.5.2+ds1-1","1.5.2+ds1-2","1.5.3+ds1-1","1.5.3+ds1-2"],"ecosystem_specific":{"urgency":"unimportant"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-117556.json"}},{"package":{"name":"zchunk","ecosystem":"Debian:14","purl":"pkg:deb/debian/zchunk?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.5.1+ds1-1","1.5.2+ds1-1","1.5.2+ds1-2","1.5.3+ds1-1","1.5.3+ds1-2"],"ecosystem_specific":{"urgency":"unimportant"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-117556.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"}]}