{"id":"CVE-2026-117556","aliases":["AZL-111188","DEBIAN-CVE-2026-117556","EUVD-2026-110834","GHSA-xcf7-q4j8-4wvv","SUSE-SU-2026:24640-1","SUSE-SU-2026:24657-1","SUSE-SU-2026:5138-1","UBUNTU-CVE-2026-117556","openSUSE-SU-2026:22250-1"],"status":"published","title":"zchunk before 1.5.5 Heap Out-of-Bounds Read via read_preface()","description":"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.","severity":{"version":"4.0","score":5.3,"vector":"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","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00328,"percentile":0.26252,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-125"],"published":"2026-10-27T13:07:51Z","modified":"2026-11-12T17:23:20Z","fixes":[{"ecosystem":"Azure Linux:3","package":"zchunk","fixed_in":["1.5.5-1"],"sources":["osv"]},{"ecosystem":"SUSE:Linux Micro 6.2","package":"zchunk","fixed_in":["1.5.1-160000.3.1"],"sources":["osv"]},{"ecosystem":"SUSE:Linux Enterprise Server 16.0","package":"zchunk","fixed_in":["1.5.1-160000.3.1"],"sources":["osv"]},{"ecosystem":"SUSE:Linux Enterprise Server for SAP applications 16.0","package":"zchunk","fixed_in":["1.5.1-160000.3.1"],"sources":["osv"]},{"ecosystem":"SUSE:Linux Enterprise Module for Basesystem 15 SP7","package":"zchunk","fixed_in":["1.5.1-150700.3.3.1"],"sources":["osv"]},{"ecosystem":"openSUSE:Leap 16.0","package":"zchunk","fixed_in":["1.5.1-160000.3.1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Azure Linux:3","package":"zchunk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.5.5-1"}]}]},{"source":"osv","ecosystem":"Debian:12","package":"zchunk","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"]},{"source":"osv","ecosystem":"Debian:13","package":"zchunk","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"]},{"source":"osv","ecosystem":"Debian:14","package":"zchunk","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"]},{"source":"osv","ecosystem":"SUSE:Linux Micro 6.2","package":"zchunk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.5.1-160000.3.1"}]}]},{"source":"osv","ecosystem":"SUSE:Linux Enterprise Server 16.0","package":"zchunk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.5.1-160000.3.1"}]}]},{"source":"osv","ecosystem":"SUSE:Linux Enterprise Server for SAP applications 16.0","package":"zchunk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.5.1-160000.3.1"}]}]},{"source":"osv","ecosystem":"SUSE:Linux Enterprise Module for Basesystem 15 SP7","package":"zchunk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.5.1-150700.3.3.1"}]}]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"zchunk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.1.9+ds1-1","1.1.16+ds1-1"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"zchunk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.3.1+ds1-1","1.3.2+ds1-1","1.3.2+ds1-1build1","1.3.2+ds1-1build2"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"zchunk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.5.2+ds1-2","1.5.3+ds1-1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"zchunk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.5.1+ds1-1","1.5.2+ds1-1","1.5.2+ds1-2"]},{"source":"osv","ecosystem":"openSUSE:Leap 16.0","package":"zchunk","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.5.1-160000.3.1"}]}]}],"products":[{"vendor":"microsoft","product":"zchunk"},{"vendor":"zchunk","product":"zchunk"}],"references":[{"url":"https://github.com/zchunk/zchunk/issues/119","tags":["issue-tracking","report"]},{"url":"https://github.com/zchunk/zchunk","tags":["product","package","report"]},{"url":"https://github.com/zchunk/zchunk/commit/02b371a64bf98245df97315d07c684a0ca5ea1df","tags":["patch","fix","report"]},{"url":"https://github.com/zchunk/zchunk/releases/tag/1.5.5","tags":["release-notes","advisory","report"]},{"url":"https://github.com/zchunk/zchunk/blob/1.5.4/src/lib/header.c#L167","tags":["technical-description","article","report"]},{"url":"https://www.vulncheck.com/advisories/zchunk-before-1.5.5-heap-out-of-bounds-read-via-read-preface","tags":["third-party-advisory","advisory","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-117556","tags":["web","advisory"]},{"url":"https://github.com/advisories/GHSA-xcf7-q4j8-4wvv"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/117xxx/CVE-2026-117556.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-117556","tags":["advisory"]},{"url":"https://www.suse.com/support/update/announcement/2026/suse-su-202624640-1/","tags":["advisory"]},{"url":"https://bugzilla.suse.com/1288144","tags":["report"]},{"url":"https://www.suse.com/security/cve/CVE-2026-117556","tags":["web"]},{"url":"https://www.suse.com/support/update/announcement/2026/suse-su-202624657-1/","tags":["advisory"]},{"url":"https://www.suse.com/support/update/announcement/2026/suse-su-20265138-1/","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-117556","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-117556","tags":["report"]},{"url":"","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-117556","title":"zchunk before 1.5.5 Heap Out-of-Bounds Read via read_preface()","description":"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.","status":"published","published":"2026-10-27T13:07:51.708Z","modified":"2026-10-28T16:17:15.487Z","cvss":[{"version":"4.0","score":5.3,"vector":"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","level":"medium","assessor":"cna"},{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-125"],"updated_at":"2026-11-02T14:20:13.272106Z"}],"euvd":[{"id":"EUVD-2026-110834","description":"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.","status":"published","published":"2026-10-27T13:07:51Z","modified":"2026-10-28T16:17:15Z","cvss":[{"version":"4.0","score":5.3,"vector":"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","level":"medium"}],"updated_at":"2026-11-02T16:59:20.41252Z"}],"ghsa":[{"id":"GHSA-xcf7-q4j8-4wvv","title":"zchunk before 1.5.5 contains a heap out-of-bounds read vulnerability in read_preface() in src/lib...","description":"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.","status":"published","published":"2026-10-27T15:32:44Z","modified":"2026-10-27T15:32:48Z","cvss":[{"version":"4.0","score":5.3,"vector":"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","level":"medium"},{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L","level":"medium"}],"cwes":["CWE-125"],"updated_at":"2026-11-02T15:14:29.466605Z"}],"nvd":[{"id":"CVE-2026-117556","description":"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.","status":"published","published":"2026-10-27T14:16:36.34Z","modified":"2026-10-28T17:18:13.257Z","cvss":[{"version":"4.0","score":5.3,"vector":"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","level":"medium","assessor":"secondary"},{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L","level":"medium","assessor":"secondary"}],"cwes":["CWE-125"],"updated_at":"2026-11-02T14:13:03.746397Z"}],"osv":[{"id":"CVE-2026-117556","title":"zchunk before 1.5.5 Heap Out-of-Bounds Read via read_preface()","description":"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.","status":"published","published":"2026-10-27T13:07:51.708Z","modified":"2026-11-11T17:27:07.289796032Z","cvss":[{"version":"4.0","score":5.3,"vector":"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","level":"medium"}],"cwes":["CWE-125"],"updated_at":"2026-11-10T14:01:18.284715Z"},{"id":"DEBIAN-CVE-2026-117556","description":"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.","status":"published","published":"2026-10-27T14:16:36.34Z","modified":"2026-10-29T10:00:17.148990222Z","cvss":[{"version":"4.0","score":5.3,"vector":"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","level":"medium"}],"updated_at":"2026-11-02T15:45:50.923612Z"},{"id":"UBUNTU-CVE-2026-117556","description":"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.","status":"published","published":"2026-10-27T14:16:00Z","modified":"2026-10-28T20:17:46.303811101Z","cvss":[{"version":"3.1","score":4.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L","level":"medium"},{"version":"4.0","score":5.3,"vector":"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","level":"medium"}],"updated_at":"2026-11-02T16:56:00.081948Z"},{"id":"AZL-111188","title":"CVE-2026-117556 affecting package zchunk for versions less than 1.5.5-1","description":"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.","status":"published","published":"2026-10-27T14:16:36Z","modified":"2026-11-02T14:15:56.609245427Z","updated_at":"2026-11-02T15:28:02.368326Z"},{"id":"openSUSE-SU-2026:22250-1","title":"Security update for zchunk","description":"This update for zchunk fixes the following issue:\n\n- CVE-2026-117556: heap out-of-bounds read in `read_preface()` allows attackers to cause an application crash via a\n  crafted `.zck` file (bsc#1288144).\n","status":"published","published":"2026-11-06T13:41:18Z","modified":"2026-11-11T17:23:13.172944529Z","updated_at":"2026-11-11T17:47:15.466074Z"},{"id":"SUSE-SU-2026:24640-1","title":"Security update for zchunk","description":"This update for zchunk fixes the following issue:\n\n- CVE-2026-117556: heap out-of-bounds read in `read_preface()` allows attackers to cause an application crash via a\n  crafted `.zck` file (bsc#1288144).\n","status":"published","published":"2026-11-06T13:41:36Z","modified":"2026-11-12T17:23:19.557117622Z","updated_at":"2026-11-12T18:02:05.26944Z"},{"id":"SUSE-SU-2026:24657-1","title":"Security update for zchunk","description":"This update for zchunk fixes the following issue:\n\n- CVE-2026-117556: heap out-of-bounds read in `read_preface()` allows attackers to cause an application crash via a\n  crafted `.zck` file (bsc#1288144).\n","status":"published","published":"2026-11-06T13:41:36Z","modified":"2026-11-12T17:23:20.311896976Z","updated_at":"2026-11-12T18:02:05.26944Z"},{"id":"SUSE-SU-2026:5138-1","title":"Security update for zchunk","description":"This update for zchunk fixes the following issue:\n\n- CVE-2026-117556: heap out-of-bounds read in `read_preface()` allows attackers to cause an application crash via a\n  crafted `.zck` file (bsc#1288144).\n","status":"published","published":"2026-11-09T13:00:49Z","modified":"2026-11-10T13:15:09.748344295Z","updated_at":"2026-11-10T13:29:51.103746Z"}]}}