{"id":"DEBIAN-CVE-2026-77118","details":"A heap out-of-bounds write exists in the Photo CD (PCD) decoder of GraphicsMagick. In DecodeImage() (coders/pcd.c), the Huffman delta loop advances its output pointer with q++ after every decoded delta and never checks it against the end of the heap-allocated luma/chroma plane buffers. The pointer is repositioned only when a sync marker introduces a new plane/row; between sync markers the run length is bounded solely by the input.    A crafted PCD file that positions the pointer near the end of a plane and then supplies a long run of deltas with no intervening sync therefore walks the pointer past the end of the allocation and writes through it. Processing an untrusted PCD file — for example with gm convert or gm identify, or through any application linked against libGraphicsMagick — can corrupt heap memory beyond the buffers.","modified":"2026-10-01T03:03:42.460508520Z","published":"2026-08-20T13:19:07.077Z","upstream":["CVE-2026-77118"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-77118"}],"affected":[{"package":{"name":"graphicsmagick","ecosystem":"Debian:12","purl":"pkg:deb/debian/graphicsmagick?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.4+really1.3.40-4","1.4+really1.3.40-4+deb12u1","1.4+really1.3.41-1","1.4+really1.3.42-1","1.4+really1.3.42-1.1","1.4+really1.3.42-1.1~exp1","1.4+really1.3.43-1","1.4+really1.3.44-1","1.4+really1.3.45+hg17689-1","1.4+really1.3.45+hg17692-1","1.4+really1.3.45+hg17696-1","1.4+really1.3.45-1","1.4+really1.3.46-1","1.4+really1.3.46-2","1.4+really1.3.48-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-77118.json"}},{"package":{"name":"graphicsmagick","ecosystem":"Debian:13","purl":"pkg:deb/debian/graphicsmagick?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.4+really1.3.45+hg17696-1","1.4+really1.3.46-1","1.4+really1.3.46-2","1.4+really1.3.48-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-77118.json"}},{"package":{"name":"graphicsmagick","ecosystem":"Debian:14","purl":"pkg:deb/debian/graphicsmagick?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.4+really1.3.48-1"}]}],"versions":["1.4+really1.3.45+hg17696-1","1.4+really1.3.46-1","1.4+really1.3.46-2"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-77118.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/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"}]}