{"id":"CVE-2026-120251","title":"imagecodecs 2026.3.6 through 2026.10.10 Infinite Loop via ccittfax4_decode()","summary":"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…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","cvssSource":"cna","cwe":["CWE-835"],"vendor":"cgohlke","product":"imagecodecs","affected":["imagecodecs >= 2026.3.6 <= 2026.10.10"],"ssvc":{"exploitation":"poc","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-06T18:56:56.662592Z"},"exploitAvailable":true,"published":"2026-11-01","updated":"2026-11-06","sourceUpdated":"2026-11-06T18:57:26.486Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-120251","references":[{"url":"https://github.com/cgohlke/imagecodecs/issues/158","label":"GitHub Issue #158"},{"url":"https://github.com/cgohlke/imagecodecs/blob/v2026.10.10/3rdparty/ccitt/ccitt.c#L1449"},{"url":"https://github.com/cgohlke/imagecodecs"},{"url":"https://www.vulncheck.com/advisories/imagecodecs-2026.3.6-through-2026.10.10-infinite-loop-via-ccittfax4-decode","label":"VulnCheck Advisory: imagecodecs 2026.3.6 through 2026.10.10 Infinite Loop via ccittfax4_decode()"}],"tags":["cve.org","exploit-available"],"epss":0.00124,"epssPercentile":0.02133,"ingestedAt":"2026-11-05T18:28:50.670Z","slug":"CVE-2026-120251","body":"## Overview\n\nimagecodecs 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.\n\n## Affected\n\n- `imagecodecs >= 2026.3.6 <= 2026.10.10`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":42,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":12,"ransomware":0},"changes":[{"seq":235646,"id":"CVE-2026-120251","ts":1793995428825,"field":"exploit_available","old":"false","new":"true"}]}