{"id":"DEBIAN-CVE-2026-96640","details":"Pillow is a Python imaging library. From 5.1.0 until 13.0.0, PdfParser.linearize_page_tree() in src/PIL/PdfParser.py treats a PDF /Pages graph as a tree without tracking duplicate indirect references. When Image.save(..., format=\"PDF\", append=True) processes an attacker-controlled existing PDF whose /Kids arrays repeatedly reference the same child /Pages node, Pillow expands the shared subtree as distinct pages. A compact malformed PDF can therefore create exponentially many page references and consume disproportionate CPU before the append completes. This issue is fixed in version 13.0.0.","modified":"2026-10-23T16:02:56.266571081Z","published":"2026-10-21T21:20:32.357Z","upstream":["CVE-2026-96640"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-96640"}],"affected":[{"package":{"name":"pillow","ecosystem":"Debian:12","purl":"pkg:deb/debian/pillow?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["10.0.0-1","10.1.0-1","10.2.0-1","10.3.0-1","10.3.0-2","10.4.0-1","10.4.0-1.1","11.1.0-1","11.1.0-2","11.1.0-3","11.1.0-4","11.1.0-5","11.2.1-1","11.3.0-1","12.0.0-1","12.1.0-1","12.1.1-1","12.1.1-2","12.2.0-1","12.3.0-1","13.0.0-1","9.4.0-1.1","9.4.0-1.1+deb12u1","9.5.0-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-96640.json"}},{"package":{"name":"pillow","ecosystem":"Debian:13","purl":"pkg:deb/debian/pillow?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["11.1.0-5","11.1.0-5+deb13u1","11.1.0-5+deb13u2","11.1.0-5+deb13u3","11.1.0-5+deb13u4","11.2.1-1","11.3.0-1","12.0.0-1","12.1.0-1","12.1.1-1","12.1.1-2","12.2.0-1","12.3.0-1","13.0.0-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-96640.json"}},{"package":{"name":"pillow","ecosystem":"Debian:14","purl":"pkg:deb/debian/pillow?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["11.1.0-5","11.2.1-1","11.3.0-1","12.0.0-1","12.1.0-1","12.1.1-1","12.1.1-2","12.2.0-1","12.3.0-1","13.0.0-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-96640.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/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"}]}