{"affected":[{"defaultStatus":"unaffected","ecosystem":"pypi","packageName":"imagecodecs","product":"imagecodecs","source":"CNA: VulnCheck","vendor":"cgohlke","versions":[{"lessThanOrEqual":"2026.10.10","status":"affected","version":"2026.3.6","versionType":"custom"}]}],"cveId":"CVE-2026-120251","cwes":["CWE-835"],"description":"imagecodecs 2026.3.6 through 2026.10.10 contains an infinite loop vulnerability in ccitt_fax4_decode_size() that allows attackers to hang the calling process by supplying a crafted CCITT Group 4 stream. Attackers can provide an 8-byte G4 stream lacking EOFB to ccittfax4_decode() or the numcodecs Ccittfax4 codec, consuming full CPU until the process is killed.","epss":{"date":"2026-11-06","percentile":0.02136,"score":0.00124},"exploits":[{"kind":"exploit","source":"ADP: CISA-ADP","url":"https://github.com/cgohlke/imagecodecs/issues/158"}],"kev":null,"metrics":[{"score":6.8,"severity":"medium","source":"CNA: VulnCheck","vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","version":"4.0"},{"score":5.5,"severity":"medium","source":"CNA: VulnCheck","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","version":"3.1"},{"score":6.8,"severity":"medium","source":"NVD: disclosure@vulncheck.com","vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/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","version":"4.0"},{"score":5.5,"severity":"medium","source":"NVD: disclosure@vulncheck.com","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","version":"3.1"}],"modifiedAt":1793991446486,"publishedAt":1793494634911,"references":[{"source":"CNA: VulnCheck","tags":["issue-tracking"],"url":"https://github.com/cgohlke/imagecodecs/issues/158"},{"source":"CNA: VulnCheck","tags":["technical-description"],"url":"https://github.com/cgohlke/imagecodecs/blob/v2026.10.10/3rdparty/ccitt/ccitt.c#L1449"},{"source":"CNA: VulnCheck","tags":["product"],"url":"https://github.com/cgohlke/imagecodecs"},{"source":"CNA: VulnCheck","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/imagecodecs-2026.3.6-through-2026.10.10-infinite-loop-via-ccittfax4-decode"},{"source":"ADP: CISA-ADP","tags":["exploit"],"url":"https://github.com/cgohlke/imagecodecs/issues/158"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://github.com/cgohlke/imagecodecs"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://github.com/cgohlke/imagecodecs/blob/v2026.10.10/3rdparty/ccitt/ccitt.c#L1449"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://github.com/cgohlke/imagecodecs/issues/158"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://www.vulncheck.com/advisories/imagecodecs-2026.3.6-through-2026.10.10-infinite-loop-via-ccittfax4-decode"}],"remediation":[],"revision":"dc9c1b643dcddfa36606d7d76d01a341b70d31c1842549cd08c1dc77e5e4f5f4","sources":[{"modifiedAt":1793991446486,"name":"CNA: VulnCheck","retrievedAt":1793992229328,"url":"https://www.cve.org/CVERecord?id=CVE-2026-120251"},{"modifiedAt":1793648063993,"name":"NVD","retrievedAt":1793665770086,"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-120251"},{"modifiedAt":null,"name":"FIRST EPSS","retrievedAt":1793992246095,"url":"https://api.first.org/data/v1/epss?cve=CVE-2026-120251"}],"ssvc":{"assessedAt":1793991416662,"automatable":"no","exploitation":"poc","source":"ADP: CISA-ADP","technicalImpact":"partial"},"status":"published","title":"imagecodecs 2026.3.6 through 2026.10.10 Infinite Loop via ccittfax4_decode()","updatedAt":1793992246095}